In order to investigate the effects of seed rate on root twining power and seedling quality of machine-transplanted super rice cultivars, Yongyou 12 and Zhongzheyou No.l, total 6 seed rates were arranged, and the grow...In order to investigate the effects of seed rate on root twining power and seedling quality of machine-transplanted super rice cultivars, Yongyou 12 and Zhongzheyou No.l, total 6 seed rates were arranged, and the growth characteris- tics, quality and root twining power of machine-transplanted rice seedlings were studied. The results showed that seed rate had great effects on root twining power and qualityof rice seedlings; with the increase of seed rate, the root twining power of rice seedlings was increased, but the quality of rice seedlings was significantly reduced; under the condition of high seed rate, rice seedlings were weak with less accumulate dry matter and nonuniform growth, and the proportion of weak seedlings was higher. When the seed rate of both rice cultivars was reduced by 10 g/tray, the average seedling height was increased by 0.5 cm, leaf age was increased by 0.1, stem base diameter was increased by 0.1 cm, and root number per plant was increased by 0.3. When the seed rate was increased by 10 g/tray, the accumulated dry matter per plant was reduced by 5.1 mg. With the increase of seed rate, the seedling quality of Zhongzheyou No.1 was decreased rapidly, and the proportion of weak seedlings was increased rapidly. However, Yongyou 12 has a larger elasticity in seed rate. When the seed rate reached to 50 g/tray, blanket seedlings of Yongy- ou 12 were nursed with uniform growth and higher quality, but the shoots were sparse with lower leaf area index. However, when the seed rate was up to 50 g/tray, blanket seedlings of Zhongzheyou No.1 were nursed with uniform growth and higher quality, as well as higher-density shoots. From a comprehensive point of view, the optimum seed rates of Yongyou 12 and Zhongzheyou No.1 were 65 and 50 g/tray, respectively.展开更多
Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season...Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.展开更多
The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme na...The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme natural high temperature on seed setting rate of different rice cultivar （line）. The results showed that the contin- uous high temperature showed certain effects on the seed setting rates of tested materials, and significant differences were shown in seed setting rate among differ- ent rice cultivars （lines）. The seed setting rates differed significantly among indica F1 hybrids derived from different sterile and restorer lines, indicating that the sterile and restorer lines had great effects on heat tolerances of different F~ hybrids. The cor- relation analysis showed that the seed setting rates of conventional indica restorer lines and conventional japonica rice cultivars （lines） were negatively related to the daily highest temperature （P〉0.05）, and the seed setting rates of indica F1 hybrids were positively related to the seed setting rates of their restorer lines. Total four in- dica restorer lines, including Ninghuiguangkangzhan, Shuhui 527, Chenghui 3203 and Xianyin-8, and four new japonica rice cultivars （lines）, including Wuyinjinghui （B2）, Nanjing 4//W3660/Nanjing 44 （B12） and Wuyun 2330/JD6011 （B22） were pre- liminarily screened, and their seed setting rates were all close to the normal level （90%）. The screened rice cultivars （lines） showed higher heat tolerances.展开更多
In this study,Zhongzao 39,Zhuliangyou 189,Hyou 518 and Taiyou 390 four rice cultivars were used to explore the effects of increased seedling age on the seedling quality,tillering rate,panicle-bearing tiller rate,bioma...In this study,Zhongzao 39,Zhuliangyou 189,Hyou 518 and Taiyou 390 four rice cultivars were used to explore the effects of increased seedling age on the seedling quality,tillering rate,panicle-bearing tiller rate,biomass,and seed yield attributes with a low seeding rate grown under machine-transplanted conditions.The results showed that compared to 20-day-old(15)rice seedlings with a conventional seeding rate,rice seedlings with a low seeding rate showed a significantly increased grain yield at higher seedling ages(5~10 d).In seedlings with a low seeding rate,the average number of spikelets per panicle was 18.9%higher in 25-day-old early rice and 15.9%higher in 20-day-old late rice compared to seedlings with a conventional seeding rate.There was no significant difference in panicles per square meter between the seedlings with a low seeding rate and the seedlings with a conventional seeding rate.In the low seeding rate plants,an increased seedling age(5~10 d)resulted in higher seedling quality and higher tillering and panicle-bearing tiller rates.Our results suggested that the prolonged aging of the seedlings with a low seeding rate compensated for the negative influence of delayed transplantation under machine-transplanted conditions.展开更多
[Objective] This study was to investigate the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight of hybrid rice combinations. [Method] The seed setting rate and 1 000-grain weight of 10 new ...[Objective] This study was to investigate the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight of hybrid rice combinations. [Method] The seed setting rate and 1 000-grain weight of 10 new sterile indica restorer lines planted in pots under enhanced UV-B radiation and fluorescent lamps （control） were respectively measured, and the differences were compared. [Result] The enhanced UV-B radiation significantly reduced the seed setting rate of indica restorer lines, and the differences between that UV-B radiation treatment and control all reached extremely significant level. In addition, the enhanced UV-B radiation reduced the 1 000-grain weight of most indica restorer lines, and compared with that of control the difference achieved significant or very significant level. However, the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight differed to different indica restorer lines, and the differences among restorer lines tested were significant or very significant, which indicated the possibility to screen antiUV-B radiation rice materials and combinations. Finally, the indica restorer lines 09R-14, Luhui 37 and 10R-7703 which were strongly resistant to UV-B radiation were screened out. [Conclusion] This study laid foundation for breeding hybrid rice varieties resistance to UV-B radiation.展开更多
Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)...Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons.Suitable sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–2015.Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages.Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain yield.SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or SR112.5.For productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three seasons.The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years.Ear number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was high.Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods.By selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved.Based on these results,we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.展开更多
Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing meth...Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing method does not facilitate mechanization during sowing.The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots.A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180000(S180),225000(S225),and 270000 seeds ha^-1(S270)with that of double-seed sowing at 270000 seeds ha^-1(D270)using a completely randomized block design with four replications.And the root bleeding sap rate,nutrient content,and the main hormone contents in root bleeding sap were also comparatively investigated.Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270),S225 yielded better than the other two single-seed sowing treatments(S180 and S270).The increased pod yield in single-seed sowing at 225000 seeds ha^-1 was mainly due to the higher pod dry weight per plant and harvest index.The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate,content of free amino acids,soluble sugars,K^+,Mg^2+,Zn^2+,and Ca^2+of the individual plant root.The improved activity of root reductive,nitrate reductase(NR)and ATPase and higher zeatin and zeatin riboside(Z+ZR)content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut.Single-seed sowing at a moderate seeding rate(S225)is a potential practice to increase pod yield and to save seed cost.展开更多
Durum wheat (Triticum durum Desf.) is a market class of wheat subject to price discounts in the marketplace if quality standards are not met. This study was conducted in order to determine how certain agronomic practi...Durum wheat (Triticum durum Desf.) is a market class of wheat subject to price discounts in the marketplace if quality standards are not met. This study was conducted in order to determine how certain agronomic practices might impact durum wheat quality. The effects of planting date (PD), cultivar, and seeding rate on agronomic and semolina quality traits were investigated in field trials conducted near Hettinger and Minot, ND in 2014 and 2015. The interaction of PD and cultivar was significant for many of the traits evaluated. There was a significant PD X cultivar interaction or PD and cultivar effect for yield in all environments. Planting date X cultivar interacted for test weight at all environments. In general, a delay in PD resulted in a significant decrease in yield and test weight for all cultivars. However, Carpio yielded more than other cultivars in high yielding environments while the yield and test weight of Joppa was more adversely affected by delays in PD. Seeding rate did not have a consistent effect on any agronomic or quality trait. Protein content, kernel yellow pigment content, falling number (FN), and vitreous kernels were more dependent on cultivar, regardless of PD and environment. Semolina extraction, gluten index (GI), and wet gluten (WG) values tended to decrease with a delay in PD. These data continue to support cultivar selection as a critical component for obtaining high-yielding, high-quality durum wheat. However, PD and environment can impact certain agronomic and end-use traits, regardless of cultivar grown.展开更多
[Objectives] This study was conducted to investigate the effects of different proportions of spent Pleurotus ostreatus substrate on the germination and seedling growth of mung beans. [Methods] The cellulose-degrading ...[Objectives] This study was conducted to investigate the effects of different proportions of spent Pleurotus ostreatus substrate on the germination and seedling growth of mung beans. [Methods] The cellulose-degrading bacteria HB8 and HF1 were mixed with a commercially available microbial composting agent, respectively, for the composting of spent P. ostreatus substrate. Mung beans were cultivated with different proportions of spent mushroom substrate compost and soil. The seed germination rate, plant height, fresh weight and chlorophyll content of mung bean were used as indicators to investigate the effects of the organic fertilizer from spent P. ostreatus substrate on the growth of mung bean seedlings. [Results] The addition of cellulose-degrading bacteria can significantly improve the composting effect of the spent mushroom substrate. After 8 d of cultivation of mung beans with different ratios of the mushroom substrate organic fertilizer, 50% of the organic fertilizer can make the plant height, fresh weight and leaf chlorophyll content of mung bean seedlings reach the highest value and was suitable for mung bean breeding and cultivation. [Conclusions] This study provides scientific basis and technical indicators for the rapid and harmless treatment of spent mushroom substrate and its application in crop cultivation and nursery.展开更多
Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-...Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-accumulation have not yet been well investigated.AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds.Here we conducted three experiments,greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice(DSR)system,using elite lines incorporating AG1,AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On(AG1)and Ma-Zhan Red(AG2).In germinating seedlings,soluble sugars increased,while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil.Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage.But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017.Plant survival rate was positively correlated with the stem NSC at the early vegetative stage(21 days after sowing),and stem NSC was positively associated with plant height at different growth stages.Among the tested seeding rate,the most suitable seeding rate,4 g/m2 with shallow burial depth(0.5 cm),resulted in better seedling establishment,relatively higher seedling vigor index and higher leaf area index under flooding in DSR system.Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate,germination rate,and growth and biomass production.展开更多
The paper was to study the effects of seeding rate, water and fertilizer （ N, P, K） coupling on grass yield of forage millet Jigu No. 18 （Setaria itlica）. A quadratic regression otthogonal rotation combination wit...The paper was to study the effects of seeding rate, water and fertilizer （ N, P, K） coupling on grass yield of forage millet Jigu No. 18 （Setaria itlica）. A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet （Y） and soil moisture content （ x1 ）, N fertilizer （x2 ）, P fertilizer （x3 ）, K fertilizer （x4） and seeding rate （x5 ） was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 ＋ 1. 052x^x2 ＋ 1. 604xIx3 ＋ 12. 953xt x5 - 0. 173x2x3 ＋ 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% （ 3 288.98 yuan/hm^2 ） compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province.展开更多
[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object...[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object,the seed yield was determined by staged harvesting combined with the actual cutting and measuring method;and the caffeoylquinic acids(CQA)were used as the characterization indexes,and high performance liquid chromatography was used to determine the contents of 3,4-CQA,3,5-CQA and 4,5-CQA of V.anthelmintica seeds under different seeding rate+light treatments,so as to compare the changes in seed yield and chemical composition of V.anthelmintica under different seeding rates and light factors.[Results]In Moyu County,Hetian and similar areas,the suitable planting rate of V.anthelmintica was in the range of 13.5-15.0 kg/hm^(2).For different harvesting purposes,the optimal seeding rate and light conditions of V.Anthelmintica were different.[Conclusions]The seeding rate and light conditions can be used to interfere with the seed yield and quality of V.anthelmintica.展开更多
[Objective] To find a processing method to increase germination rate of Wada alfalfa seeds. [Method] Five processing methods were used to treat Wada alfaffa seeds, including immersion in hot water, immersion in 98% co...[Objective] To find a processing method to increase germination rate of Wada alfalfa seeds. [Method] Five processing methods were used to treat Wada alfaffa seeds, including immersion in hot water, immersion in 98% concentrated sulfuric acid, immersion in 100 g/L potassium nitrate, immersion in hot water after rubbing seed capsule, immersion in 30% （ V~ V） hydrogen peroxide. After treatment, germination energy, germination rate, germination index and vitality index were detected. [ Result] The Wada alfaffa seeds immersed in 25℃ water for 25 min after rubbing seed capsule had the highest germination rate （81.3%）, followed by that of seeds immersed in 100 g/L potassium nitrate for 2 h, that of seeds immersed in 50℃ water, and that of seeds immersed in 30% hydrogen peroxide for 5 min in order. The worst germination appeared in the seeds im- mersed in 98% concentrated sulfuric acid. [ Conclusion] Immersion in 25℃ water for 25 min after rubbing seed capsule is the best method to increase germination rate of Wada alfaffa seeds.展开更多
Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots...Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots pine (Pin us sylvestris var.mangolica),Dahurian larch (Larix gmelini), korean spruce (Picea koraiensis), anur cork tree(Phellodendron amurensis). manchurian ash (Fradinus mandshurica) and anur linden (Tilia amurensis) were studied in this paper. The results show that the survival rate, stocking Percentage and the growth of height and collar diameter of the I class seedlings are better than that of the n and III classes seedlings. so it is very important to select I class seedlings for increasing the quality of afforestation.展开更多
<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font...<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2017 and 2017</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">2018 growing seasons.</span><span style="color:red;"> </span><span style="font-family:Verdana;">This study was conducted using two irrigation methods, sprinkler and surface irrigation, for each of them had three Tillage methods (zero-tillage</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> medium-tillage</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> deep-tillage) and each tillage system had four seeding rate of wheat yield (120</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">180</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">240</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">300) kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">Results indicated that the consumptive water use was 557.5 and</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">535.9 mm for surface irrigation and 460.9 and 442.6 mm for sprinkler irrigation in </span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">2016-2017 and 2017-2018 growing seasons. Sprinkler irrigation significantly increased the flag leaf area with no significant effect on plant height. However, the minimum tillage and seeding rate (240 kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) significantly increased the plant height and flag leaf </span><span style="font-family:Verdana;">area in both growing seasons. For the grain yield, the sprinkler irrigation, m</span><span style="font-family:Verdana;">inimum tillage, and seeding rate (240 </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) also increased the plant height and flag leaf area by 13%, 10, % 11%, 11%, 12%, and 14% in both growing seasons, respectively, through an increased number of spikes/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, the number of grain spike-1, and 1000-grain weight in both growing seasons, respe</span></span><span style="font-family:Verdana;">ctively. Interestingly the grain yield was increased by 33% and 32% in both growing seasons under the effects of these three factors altogether, respectively. It can be concluded that these factors act synergistically, resulting in a significant improvement in the wheat grain-yield of, less consumptive water use, and high water use efficiency.</span>展开更多
[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was...[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was carried out by setting five N fertilizer treatments and three density levels.[Results] Increasing seeding density and N application rate could improve the seed yield of rape. The suitable N application rate for the three densities were calculated using the fitted fertilizer efficiency models, respectively, to be 186.77, 221.35 and 236.14 kg/hm^2, at which the yields were the highest. The results showed that in this area, the seeding density of direct-seeding rape could be selected in the range of 6.0×10^5-7.5×10^5 plants/hm^2, and the suitable N application rate could be in the range of 221.35-236.14 kg/hm^2.[Conclusions] This study provides a theoretical basis for the maximization of spatial resource and efficient utilization of fertilizer.展开更多
基金Supported by National Rice Industry Technology System(CARS-01-04A)National Key Technology Research and Development Program(2012BAD07B02)+1 种基金Ministry of Science and Technology’s Special Fund for Technology Development and Research of Research Institutes(2013EG134237)National Nonprofit Institute Research Grant of CATAS-TCGRI(2012RG005-3)~~
文摘In order to investigate the effects of seed rate on root twining power and seedling quality of machine-transplanted super rice cultivars, Yongyou 12 and Zhongzheyou No.l, total 6 seed rates were arranged, and the growth characteris- tics, quality and root twining power of machine-transplanted rice seedlings were studied. The results showed that seed rate had great effects on root twining power and qualityof rice seedlings; with the increase of seed rate, the root twining power of rice seedlings was increased, but the quality of rice seedlings was significantly reduced; under the condition of high seed rate, rice seedlings were weak with less accumulate dry matter and nonuniform growth, and the proportion of weak seedlings was higher. When the seed rate of both rice cultivars was reduced by 10 g/tray, the average seedling height was increased by 0.5 cm, leaf age was increased by 0.1, stem base diameter was increased by 0.1 cm, and root number per plant was increased by 0.3. When the seed rate was increased by 10 g/tray, the accumulated dry matter per plant was reduced by 5.1 mg. With the increase of seed rate, the seedling quality of Zhongzheyou No.1 was decreased rapidly, and the proportion of weak seedlings was increased rapidly. However, Yongyou 12 has a larger elasticity in seed rate. When the seed rate reached to 50 g/tray, blanket seedlings of Yongy- ou 12 were nursed with uniform growth and higher quality, but the shoots were sparse with lower leaf area index. However, when the seed rate was up to 50 g/tray, blanket seedlings of Zhongzheyou No.1 were nursed with uniform growth and higher quality, as well as higher-density shoots. From a comprehensive point of view, the optimum seed rates of Yongyou 12 and Zhongzheyou No.1 were 65 and 50 g/tray, respectively.
基金supported by the National Natural Science Foundation of China(31971845 and 32101819)the earmarked fund for China Agriculture Research System(CARS-01-20)the China Postdoctoral Science Foundation(2021M691179)。
文摘Nitrogen(N) and seeding rates are important factors affecting grain yield and N use efficiency(NUE) in directseeded rice. However, these factors have not been adequately investigated on direct-seeded and double-season rice(DDR) in Central China. The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR. Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha–1with a total growth duration of 85 to 97 days across all treatments with N application. Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield. Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates. The moderate N rates of 100–150 and 70–120 kg N ha–1in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR. Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity(INS) between the two seasons. Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.
基金Supported by National Natural Science Foundation of China(31201181)Earmarked Fund for China Agriculture Research System(CARS-01-47)Project for Breeding and Demonstration of New Super Rice Varieties~~
文摘The seed setting rates of total 198 rice cultivars （lines） at heading and flowering stage were investigated under the condition of extreme natural high tem- perature in 2013 so as to analyze the effect of extreme natural high temperature on seed setting rate of different rice cultivar （line）. The results showed that the contin- uous high temperature showed certain effects on the seed setting rates of tested materials, and significant differences were shown in seed setting rate among differ- ent rice cultivars （lines）. The seed setting rates differed significantly among indica F1 hybrids derived from different sterile and restorer lines, indicating that the sterile and restorer lines had great effects on heat tolerances of different F~ hybrids. The cor- relation analysis showed that the seed setting rates of conventional indica restorer lines and conventional japonica rice cultivars （lines） were negatively related to the daily highest temperature （P〉0.05）, and the seed setting rates of indica F1 hybrids were positively related to the seed setting rates of their restorer lines. Total four in- dica restorer lines, including Ninghuiguangkangzhan, Shuhui 527, Chenghui 3203 and Xianyin-8, and four new japonica rice cultivars （lines）, including Wuyinjinghui （B2）, Nanjing 4//W3660/Nanjing 44 （B12） and Wuyun 2330/JD6011 （B22） were pre- liminarily screened, and their seed setting rates were all close to the normal level （90%）. The screened rice cultivars （lines） showed higher heat tolerances.
文摘In this study,Zhongzao 39,Zhuliangyou 189,Hyou 518 and Taiyou 390 four rice cultivars were used to explore the effects of increased seedling age on the seedling quality,tillering rate,panicle-bearing tiller rate,biomass,and seed yield attributes with a low seeding rate grown under machine-transplanted conditions.The results showed that compared to 20-day-old(15)rice seedlings with a conventional seeding rate,rice seedlings with a low seeding rate showed a significantly increased grain yield at higher seedling ages(5~10 d).In seedlings with a low seeding rate,the average number of spikelets per panicle was 18.9%higher in 25-day-old early rice and 15.9%higher in 20-day-old late rice compared to seedlings with a conventional seeding rate.There was no significant difference in panicles per square meter between the seedlings with a low seeding rate and the seedlings with a conventional seeding rate.In the low seeding rate plants,an increased seedling age(5~10 d)resulted in higher seedling quality and higher tillering and panicle-bearing tiller rates.Our results suggested that the prolonged aging of the seedlings with a low seeding rate compensated for the negative influence of delayed transplantation under machine-transplanted conditions.
基金Supported by the Financial Genetic Engineering Program of Sichuan Province during the 12th Five-Year Plan Period(2011JYGC11-029)Sichuan Innovation Team Program of China Agriculture Research System+1 种基金Key Rice Breeding Technology Research and Development Program of Sichuan Province during the 12th Five-Year Plan Period(2011NZ0098-1)Key Science and Technology Program of Luzhou City(2011-N-09)~~
文摘[Objective] This study was to investigate the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight of hybrid rice combinations. [Method] The seed setting rate and 1 000-grain weight of 10 new sterile indica restorer lines planted in pots under enhanced UV-B radiation and fluorescent lamps （control） were respectively measured, and the differences were compared. [Result] The enhanced UV-B radiation significantly reduced the seed setting rate of indica restorer lines, and the differences between that UV-B radiation treatment and control all reached extremely significant level. In addition, the enhanced UV-B radiation reduced the 1 000-grain weight of most indica restorer lines, and compared with that of control the difference achieved significant or very significant level. However, the effect of enhanced UV-B radiation on seed setting rate and 1 000-grain weight differed to different indica restorer lines, and the differences among restorer lines tested were significant or very significant, which indicated the possibility to screen antiUV-B radiation rice materials and combinations. Finally, the indica restorer lines 09R-14, Luhui 37 and 10R-7703 which were strongly resistant to UV-B radiation were screened out. [Conclusion] This study laid foundation for breeding hybrid rice varieties resistance to UV-B radiation.
基金supported by the earmarked fund for China Agriculture Research System (CARS-0301-24)the National Natural Science Foundation of China (31771727)+5 种基金the National Key Technology R&D Program of China (2015BAD23B04-2)The research project was also supported by the Shanxi Scholarship Council,China (2015Key 4)the Shanxi Science and Technology Innovation Team Project,China (201605D131041)the Jinzhong Science and Technology Plan Project,China (Y172007-2)the Sanjin Scholar Support Special Funds,Chinathe Special Fund for Agro-scientific Research in the Public Interest,China (201503120)
文摘Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons.Suitable sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–2015.Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages.Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain yield.SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or SR112.5.For productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three seasons.The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years.Ear number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was high.Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods.By selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved.Based on these results,we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.
基金supported by the National Key R&D Program of China(2018YFD1000900)the National Natural Science Foundation of China(31571605,31801276)+5 种基金the Major Basic Research Project of Natural Science Foundation of Shandong Province,China(2018GHZ007)the Major Scientific and Technological Innovation Project in Shandong Province,China(2018YFJH0601)the Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2018D04,CXGC2016B03-1)the Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2018E13,CXGC2016B10,CXGC2018F6)the Major Agricultural Application Technology Innovation Project in Shandong Province,China(201706)the earmarked fund for China Agriculture Research System(CARS-13)。
文摘Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing method does not facilitate mechanization during sowing.The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots.A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180000(S180),225000(S225),and 270000 seeds ha^-1(S270)with that of double-seed sowing at 270000 seeds ha^-1(D270)using a completely randomized block design with four replications.And the root bleeding sap rate,nutrient content,and the main hormone contents in root bleeding sap were also comparatively investigated.Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270),S225 yielded better than the other two single-seed sowing treatments(S180 and S270).The increased pod yield in single-seed sowing at 225000 seeds ha^-1 was mainly due to the higher pod dry weight per plant and harvest index.The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate,content of free amino acids,soluble sugars,K^+,Mg^2+,Zn^2+,and Ca^2+of the individual plant root.The improved activity of root reductive,nitrate reductase(NR)and ATPase and higher zeatin and zeatin riboside(Z+ZR)content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut.Single-seed sowing at a moderate seeding rate(S225)is a potential practice to increase pod yield and to save seed cost.
文摘Durum wheat (Triticum durum Desf.) is a market class of wheat subject to price discounts in the marketplace if quality standards are not met. This study was conducted in order to determine how certain agronomic practices might impact durum wheat quality. The effects of planting date (PD), cultivar, and seeding rate on agronomic and semolina quality traits were investigated in field trials conducted near Hettinger and Minot, ND in 2014 and 2015. The interaction of PD and cultivar was significant for many of the traits evaluated. There was a significant PD X cultivar interaction or PD and cultivar effect for yield in all environments. Planting date X cultivar interacted for test weight at all environments. In general, a delay in PD resulted in a significant decrease in yield and test weight for all cultivars. However, Carpio yielded more than other cultivars in high yielding environments while the yield and test weight of Joppa was more adversely affected by delays in PD. Seeding rate did not have a consistent effect on any agronomic or quality trait. Protein content, kernel yellow pigment content, falling number (FN), and vitreous kernels were more dependent on cultivar, regardless of PD and environment. Semolina extraction, gluten index (GI), and wet gluten (WG) values tended to decrease with a delay in PD. These data continue to support cultivar selection as a critical component for obtaining high-yielding, high-quality durum wheat. However, PD and environment can impact certain agronomic and end-use traits, regardless of cultivar grown.
基金Supported by Scientific Research Fund of Hunan Provincial Education Department(15C0721)Hunan Provincial Innovation Platform Open Fund Project(16K047)Hunan Provincial Construct Program of the Key Discipline
文摘[Objectives] This study was conducted to investigate the effects of different proportions of spent Pleurotus ostreatus substrate on the germination and seedling growth of mung beans. [Methods] The cellulose-degrading bacteria HB8 and HF1 were mixed with a commercially available microbial composting agent, respectively, for the composting of spent P. ostreatus substrate. Mung beans were cultivated with different proportions of spent mushroom substrate compost and soil. The seed germination rate, plant height, fresh weight and chlorophyll content of mung bean were used as indicators to investigate the effects of the organic fertilizer from spent P. ostreatus substrate on the growth of mung bean seedlings. [Results] The addition of cellulose-degrading bacteria can significantly improve the composting effect of the spent mushroom substrate. After 8 d of cultivation of mung beans with different ratios of the mushroom substrate organic fertilizer, 50% of the organic fertilizer can make the plant height, fresh weight and leaf chlorophyll content of mung bean seedlings reach the highest value and was suitable for mung bean breeding and cultivation. [Conclusions] This study provides scientific basis and technical indicators for the rapid and harmless treatment of spent mushroom substrate and its application in crop cultivation and nursery.
基金This study was supported by the Lee Foundation Scholarship(PhD)through International Rice Research Institute,the PhilippinesThe authors are thankful to Melencio J.APOSTOL for his technical assistance,and to Frederickson ENTILA and Evangelina S.ELLA for helpful suggestions and comments during this study.
文摘Rice(Oryza sativa)plants acquired excess photosynthates in the form of nonstructural carbohydrates(NSCs)in their stems and grain.Despite keen interest in rice NSC,the dynamics of NSC accumulation,translocation and re-accumulation have not yet been well investigated.AG1 and AG2 QTLs associated with flooding tolerance through catalyzing starch into soluble sugar in germinating seeds.Here we conducted three experiments,greenhouse and field to lay the groundwork for large-scale diversity studies on grain NSC and some agronomic traits under direct-seeded rice(DSR)system,using elite lines incorporating AG1,AG2 and AG1-AG2 QTLs into the popular varieties PSB Rc82 and Ciherang-Sub1 along with the donors Kho Hlan On(AG1)and Ma-Zhan Red(AG2).In germinating seedlings,soluble sugars increased,while starch concentration decreased gradually especially in the tolerant checks and AG1-AG2 introgression lines under flooded soil.Soluble sugar accumulation in stem started to increase from the vegetative stage and peaked at the panicle initiation stage then gradually decreased towards the maturity stage.But Sub1-AG lines had higher sugar and starch concentrations at different growth stages than other genotypes in wet season 2016 and dry season 2017.Plant survival rate was positively correlated with the stem NSC at the early vegetative stage(21 days after sowing),and stem NSC was positively associated with plant height at different growth stages.Among the tested seeding rate,the most suitable seeding rate,4 g/m2 with shallow burial depth(0.5 cm),resulted in better seedling establishment,relatively higher seedling vigor index and higher leaf area index under flooding in DSR system.Introgression of AG1-AG2 QTLs had no any negative impact on nonstructural carbohydrate,germination rate,and growth and biomass production.
基金Special Fund for Agro-scientific Research in the Public Interest Research and Demonstration of Development and Utilization Technology of Forage Feed Resources in Pastoral Areas(20120304201)
文摘The paper was to study the effects of seeding rate, water and fertilizer （ N, P, K） coupling on grass yield of forage millet Jigu No. 18 （Setaria itlica）. A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet （Y） and soil moisture content （ x1 ）, N fertilizer （x2 ）, P fertilizer （x3 ）, K fertilizer （x4） and seeding rate （x5 ） was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 ＋ 1. 052x^x2 ＋ 1. 604xIx3 ＋ 12. 953xt x5 - 0. 173x2x3 ＋ 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% （ 3 288.98 yuan/hm^2 ） compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province.
基金Autonomous Region Science and Technology Supporting Xinjiang Project Plant Project(2016E02007)the West Light Foundation of The Chinese Academy of Sciences(2019-FPGGRC-004).
文摘[Objectives]This study was conducted to investigate the effects of seeding rate and light on the seed yield and active ingredients of Vernonia anthelmintica.[Methods]With V.anthelmintica L.Willd as the research object,the seed yield was determined by staged harvesting combined with the actual cutting and measuring method;and the caffeoylquinic acids(CQA)were used as the characterization indexes,and high performance liquid chromatography was used to determine the contents of 3,4-CQA,3,5-CQA and 4,5-CQA of V.anthelmintica seeds under different seeding rate+light treatments,so as to compare the changes in seed yield and chemical composition of V.anthelmintica under different seeding rates and light factors.[Results]In Moyu County,Hetian and similar areas,the suitable planting rate of V.anthelmintica was in the range of 13.5-15.0 kg/hm^(2).For different harvesting purposes,the optimal seeding rate and light conditions of V.Anthelmintica were different.[Conclusions]The seeding rate and light conditions can be used to interfere with the seed yield and quality of V.anthelmintica.
基金funded by the China Natural Science Foundation(30960161)
文摘[Objective] To find a processing method to increase germination rate of Wada alfalfa seeds. [Method] Five processing methods were used to treat Wada alfaffa seeds, including immersion in hot water, immersion in 98% concentrated sulfuric acid, immersion in 100 g/L potassium nitrate, immersion in hot water after rubbing seed capsule, immersion in 30% （ V~ V） hydrogen peroxide. After treatment, germination energy, germination rate, germination index and vitality index were detected. [ Result] The Wada alfaffa seeds immersed in 25℃ water for 25 min after rubbing seed capsule had the highest germination rate （81.3%）, followed by that of seeds immersed in 100 g/L potassium nitrate for 2 h, that of seeds immersed in 50℃ water, and that of seeds immersed in 30% hydrogen peroxide for 5 min in order. The worst germination appeared in the seeds im- mersed in 98% concentrated sulfuric acid. [ Conclusion] Immersion in 25℃ water for 25 min after rubbing seed capsule is the best method to increase germination rate of Wada alfaffa seeds.
文摘Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots pine (Pin us sylvestris var.mangolica),Dahurian larch (Larix gmelini), korean spruce (Picea koraiensis), anur cork tree(Phellodendron amurensis). manchurian ash (Fradinus mandshurica) and anur linden (Tilia amurensis) were studied in this paper. The results show that the survival rate, stocking Percentage and the growth of height and collar diameter of the I class seedlings are better than that of the n and III classes seedlings. so it is very important to select I class seedlings for increasing the quality of afforestation.
文摘<span style="font-family:Verdana;">A field trial was conducted at a private farm in AL-Hashimiya district Babylon Governorate—the republic of Iraq during the 2016</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">2017 and 2017</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">2018 growing seasons.</span><span style="color:red;"> </span><span style="font-family:Verdana;">This study was conducted using two irrigation methods, sprinkler and surface irrigation, for each of them had three Tillage methods (zero-tillage</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> medium-tillage</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> deep-tillage) and each tillage system had four seeding rate of wheat yield (120</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">180</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">240</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">300) kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">.</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">Results indicated that the consumptive water use was 557.5 and</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">535.9 mm for surface irrigation and 460.9 and 442.6 mm for sprinkler irrigation in </span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">2016-2017 and 2017-2018 growing seasons. Sprinkler irrigation significantly increased the flag leaf area with no significant effect on plant height. However, the minimum tillage and seeding rate (240 kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) significantly increased the plant height and flag leaf </span><span style="font-family:Verdana;">area in both growing seasons. For the grain yield, the sprinkler irrigation, m</span><span style="font-family:Verdana;">inimum tillage, and seeding rate (240 </span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">kg<span style="white-space:nowrap;">∙</span>ha</span><sup><span style="font-family:Verdana;">-1</span></sup></span><span style="font-family:;" "=""><span style="font-family:Verdana;">) also increased the plant height and flag leaf area by 13%, 10, % 11%, 11%, 12%, and 14% in both growing seasons, respectively, through an increased number of spikes/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, the number of grain spike-1, and 1000-grain weight in both growing seasons, respe</span></span><span style="font-family:Verdana;">ctively. Interestingly the grain yield was increased by 33% and 32% in both growing seasons under the effects of these three factors altogether, respectively. It can be concluded that these factors act synergistically, resulting in a significant improvement in the wheat grain-yield of, less consumptive water use, and high water use efficiency.</span>
文摘[Objectives] This study was conducted to explore the effects of different N application rates and densities on the growth and development of direct-seeding rape as well as on its yield.[Methods] A field experiment was carried out by setting five N fertilizer treatments and three density levels.[Results] Increasing seeding density and N application rate could improve the seed yield of rape. The suitable N application rate for the three densities were calculated using the fitted fertilizer efficiency models, respectively, to be 186.77, 221.35 and 236.14 kg/hm^2, at which the yields were the highest. The results showed that in this area, the seeding density of direct-seeding rape could be selected in the range of 6.0×10^5-7.5×10^5 plants/hm^2, and the suitable N application rate could be in the range of 221.35-236.14 kg/hm^2.[Conclusions] This study provides a theoretical basis for the maximization of spatial resource and efficient utilization of fertilizer.
