It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge...It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge (ITK) of the diversity of cassava varieties in terms of: their morphology, growth characteristics, uses (of tubers and leaves) and desirable characteristics. The objective is to see to what extent the objectives of the plant breeders are consistent with what farmers’ value. We performed 405 structured and semi-structured interviews with informants who were selected based on “purposive household sampling”. We found a considerable turn-over in cassava varieties, just over a third (45) have been in cultivation for at least 40 years, however, since the end of the civil war an additional 25 varieties are cultivated, while others varieties seem to have disappeared. One major issue with estimating turnover of varieties is whether the same variety might have several local names, and conversely the same name may be applied to different cultivars. Farmers overwhelmingly use ITK to select and preserve cassava germplasm for future use. Farmers have a clear preference for: sweet taste, high yield, early maturity and easy cooking and preferentially adopt cultivars that have those qualities. Cassava is primarily a human food eaten boiled or fried, some are processed into fufu and gari, and uses as livestock feed and medicine are reported but at low levels. The information produced during this study could help plant breeders choose selection criteria that will ensure their efforts are adopted and sustainable, the importance of preserving the genetic resources of local cultivars is also highlighted.展开更多
The ATP-binding cassette(ABC)transporter is a gene superfamily in plants.ATP-binding cassette subfamily C(ABCC)protein is a multidrug resistance-associated(MRP)transporter.They play various roles in plant growth,devel...The ATP-binding cassette(ABC)transporter is a gene superfamily in plants.ATP-binding cassette subfamily C(ABCC)protein is a multidrug resistance-associated(MRP)transporter.They play various roles in plant growth,development,and secondary metabolite transport.However,there are few studies on ABCC transporters in tea plants.In this study,genome-wide association study(GWAS)analysis of epigallocatechin gallate(EGCG)content in 108 strains of Kingbird revealed that CsABCCs may be involved in EGCG transport.We identified 25 CsABCC genes at the genomic level of the tea plant,their phylogenetic tree,gene structure,targeted miRNA and other bioinformatics were analyzed.The expression patterns of CsABCCs in eight different tissues and abiotic stress indicate that they have potential roles in regulating the growth,development,and defense of tea plants.The correlation analysis revealed that the expression of the CsABCC11 gene was closely related to the EGCG content in tea buds of 108 strains of the Kingbird,and the subcellular localization experiments in tobacco showed that CsABCC11 protein was localized on the plasma membrane.The virus-induced gene silencing(VIGS)strategy in tea plants further verified that CsABCC11 was involved in EGCG accumulation.Our study laid a foundation for studying the biological function of CsABCC and provided a new candidate molecular marker gene for further EGCG-related variety breeding,which will be of great interest to breeders.展开更多
[Objective] The study aimed at analyzing the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.from the Pearl River Basin in Guangdong and Guangxi Provinces.[Method] Genetic diversity of 64 local v...[Objective] The study aimed at analyzing the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.from the Pearl River Basin in Guangdong and Guangxi Provinces.[Method] Genetic diversity of 64 local varieties of Morus atropurpurea Roxb.was analyzed by ISSR molecular marker technique.The genetic relationship among these local varieties was researched by UPGMA method based on the genetic similarity coefficient.[Result] 128 bands were amplified from the total DNA of 64 local varieties using 13 ISSR primers,of which 109 bands accounting for 85.15% were polymorphic.It meant that there was rich genetic diversity among the local varieties tested.The genetic similarity coefficients among 64 local varieties were relatively high with a range of 0.500 0-0.929 7.In addition,64 local varieties were divided into two categories and the second could be further divided into 10 subcategories.It was suggested that the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.based on ISSR marker analysis has a certain correlation with geographical distribution.[Conclusion] ISSR marker technology was suitable for evaluating genetic relationship and genetic diversity of local varieties of Morus atropurpurea Roxb.in Pearl River Basin,and could provide scientific basis for DNA fingerprinting and identification of varieties of Morus atropurpurea Roxb.展开更多
A participatory breeding on Arabica coffee involving farmers and plant breeders to select superior local varieties has been conducted at Lintong highland （North Sumatra）, Gayo highland （Central Aceh, Northern Suma...A participatory breeding on Arabica coffee involving farmers and plant breeders to select superior local varieties has been conducted at Lintong highland （North Sumatra）, Gayo highland （Central Aceh, Northern Sumatra） and Kendenan Plateau （Enrekang, South Sulawesi）. The aim of using this method was to find out superior varieties of Arabica coffee having appropriate specific traits and adaptable to such locations and accelerating the process of variety adoption by local farmers. Selection process was initiated by the farmer（s） based on high yielding performance by using their native experiences. The next step was conducted by plant breeder in collaboration with coffee farmers and other relevant scientists to evaluate more detail of cup quality, resistance to leaf rust and/or parasitic nematode as well as yielding potential and agronomic traits at different farmer＇s sites for several years observations. Research finding showed that three selected varieties namely Sigarar Utang, Gayo 1 and Gayo 2 had already been released by Minister of Agriculture for commercial planting at North Sumatera and Gayo highland. They performed excellent cup profile with high yielding ability （more than 1 t/ha） and tolerant to leaf rust disease. Therefore, it could support origin specialty coffee product at Gayo and Lintong highlands. However, observation over of selected local variety at Kendenan Plateau namely Salongge variety performed lower yielding ability （below 1 t/ha） and less stable yield over years as well as more heterogenous population in their offsprings than that of existing released varieties planted at the same location. Therefore, it could not be released as local varieties which adapted to specific location.展开更多
The encapsulation in a nutritive matrix is an effective technique which allows the conservation of vitro-derived explants and protects their viability. The encapsulated propagules are generated by submerging explants ...The encapsulation in a nutritive matrix is an effective technique which allows the conservation of vitro-derived explants and protects their viability. The encapsulated propagules are generated by submerging explants in a natural polysaccharide solution of sodium alginate and calcium chloride allowing to obtain uniform capsules. In this work, we present preliminary results of a study on the effect of an encapsulation protocol on any local fruit varieties, conserved in a Regional in vitro germplasm bank.展开更多
In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to ir...In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Sérédou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.展开更多
This study explored the biodiversity in Local Thai rice Varieties （Oryza sativa L.） during May 2011 to March 2013 by conducting surveys and collecting rice varieties from 4 regions of Thailand. There are altogether ...This study explored the biodiversity in Local Thai rice Varieties （Oryza sativa L.） during May 2011 to March 2013 by conducting surveys and collecting rice varieties from 4 regions of Thailand. There are altogether 89 varieties of local rice which include 16 in Central region, 12 in Northern region, 23 in Northeastern region, and 38 in Southern region. Among them are of 2 types： 21 varieties of glutinous rice and 68 varieties of non-glutinous rice. Ecological classification suggested 72 varieties of lowland rice, 10 varieties of upland rice, and 7 varieties of floating rice. These varieties of rice were cultivated in the farmer fields of Nongbondaeng sub-district in Banbueng district of Chonburi province during the rainy season and off season between 2011 and 2013 and to capture their agricultural descriptors. Results revealed germination and seedling growth in 33 varieties. The Unknow 2 variety yields maximum weight of 6.47 grams per panicle, while Sor.6 Chumpae variety gives minimum weight of 0.85 grams per panicle. Aye Khong produces highest number of 317 filled grains per panicle, while the lowest is Sewkliang with 5 filled grains per panicle. Gumrai gives biggest size of seed of 0.47 × 1.01 mm, while Sangyod gives smallest size of 0.19 × 0.97 mm.展开更多
In tomatoes,grafting onto resistant rootstocks represents an effective strategy to control several soil-borne diseases that reduce crop profitability,especially for landraceswith little or no resistance tomultiple pat...In tomatoes,grafting onto resistant rootstocks represents an effective strategy to control several soil-borne diseases that reduce crop profitability,especially for landraceswith little or no resistance tomultiple pathogens/pests.In this study,the high-value‘Corbarino’tomato landrace was grafted onto seven commercial Solanum interspecific rootstocks to evaluate graft compatibility,yield performance,and qualitative characteristics under greenhouse healthy conditions.Three rootstocks were themost effective in improving fruit yield without negatively affecting the carpometric,technological,and health-related traits of the traditional tomato.‘Dinafort’rootstock increased fresh and dry yield,harvest index,and fruit/clusters,while mean fruit weight,shape index,total and soluble solid content,simple sugars,organic acids,flavonoids,ascorbic acid,and trans-lycopene content did not differ with respect to the ungrafted‘Corbarino’.‘Interpro’rootstock also showed promising results for the overall yield and quality traits,although it reduced the trans-lycopene content in the fruit.‘Silex’rootstock showed the highest harvest index as result of decreased vigour.The fruit quality induced by‘Silex’was satisfactory and high levels of simple sugars,flavonoids,ascorbic acid,and trans-lycopene were also observed.However,graft success,especially for‘Dinafort’and‘Silex’,needs to be improved by investigating more suitable methods for seedling production,grafting,acclimatization,etc.展开更多
Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat ...Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat use and formed through long-term natural selection and artificial selection.Because of the weak development and utilization of this breed,the economic benefits of excellent breeds have not been fully brought into play,and farmers'enthusiasm in breeding is poor,so that the number of Ebian spotted cattle has reduced year by year.In order to strengthen the protection,development and utilization of Ebian spotted cattle as a local excellent breed,combined with the third national survey of livestock and poultry genetic resources in 2021,Ebian spotted cattle was investigated,and a comprehensive,scientific and objective analysis of its population numbers was conducted.Besides,reasonable suggestions were put forward.展开更多
In Tanzania, the phenology and seasonal variations of the yields of different rice cultivars have rarely been studied, especially under fully-irrigated conditions. A trial was conducted to identify the most suitable c...In Tanzania, the phenology and seasonal variations of the yields of different rice cultivars have rarely been studied, especially under fully-irrigated conditions. A trial was conducted to identify the most suitable calendar for rice production in Tanzania under fully-irrigated conditions. Four popular rice cultivars, NERICA1, Wahiwahi, IR64 and TXD306, were transplanted monthly from January to December 2011. The four cultivars recorded similarly higher or lower yields than the annual means when transplanted in July （0.50-0.57 kg/m2） and April （0.07-0.31 kg/m2）. A yield-ranking analysis showed that plants transplanted in July was the most productive while those transplanted in April was the least productive, and also revealed a yield-seasonality for irrigated rice in Tanzania, a low-yield season （April-May）, a high-yield season （June-August）, and an unstable-yield season （September-March）. These yield seasons would appear to be closely linked to seasonal temperature variations. When transplanted in April-May, plants were exposed to very low temperatures between panicle initiation and flowering, apparently reducing yield through cold-induced sterility. Those transplanted in June-August prolonged their growth under relatively low temperatures and increased yield through increasing biomass production. In September- March, yield levels varied greatly due to the shortened phenological growth durations at higher temperatures. We conclude that under fully-irrigated conditions in Tanzania, rice should be transplanted in July to ensure the maximum production and yield stability. The yield-seasonality suggests that implementing measures to protect plants from low and high temperature stress at critical phenological stages may allow year-round rice production under fully-irrigated conditions in Tanzania.展开更多
This study focused on the investigation of crop germplasm resources in coastal areas of Shandong Province, including 132 villages in 82 towns of 34 counties. The survey collected local varieties and wild resources of ...This study focused on the investigation of crop germplasm resources in coastal areas of Shandong Province, including 132 villages in 82 towns of 34 counties. The survey collected local varieties and wild resources of grain crops, economic crops, vegetables and fruit trees, and a total of 848 samples were collected, belonging to 54 species of 39 genera in 15 families. In this study, the current situation and growth and decline conditions of crop germplasm resources were investigated, and their botanical classification and utilization importance were analyzed. Furthermore, the conservation, development and utilization of crop germplasrp resources in coastal areas of Shandong Province were also discussed in this paper.展开更多
文摘It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge (ITK) of the diversity of cassava varieties in terms of: their morphology, growth characteristics, uses (of tubers and leaves) and desirable characteristics. The objective is to see to what extent the objectives of the plant breeders are consistent with what farmers’ value. We performed 405 structured and semi-structured interviews with informants who were selected based on “purposive household sampling”. We found a considerable turn-over in cassava varieties, just over a third (45) have been in cultivation for at least 40 years, however, since the end of the civil war an additional 25 varieties are cultivated, while others varieties seem to have disappeared. One major issue with estimating turnover of varieties is whether the same variety might have several local names, and conversely the same name may be applied to different cultivars. Farmers overwhelmingly use ITK to select and preserve cassava germplasm for future use. Farmers have a clear preference for: sweet taste, high yield, early maturity and easy cooking and preferentially adopt cultivars that have those qualities. Cassava is primarily a human food eaten boiled or fried, some are processed into fufu and gari, and uses as livestock feed and medicine are reported but at low levels. The information produced during this study could help plant breeders choose selection criteria that will ensure their efforts are adopted and sustainable, the importance of preserving the genetic resources of local cultivars is also highlighted.
基金supported by the Guizhou University Talent Introduction Program([2021]05)Guizhou University Cultivation Program([2020]48)+2 种基金Institute of Technology of YF([2022]017)Guizhou Province High-Level Innovative Talents“Hundred”Level Talent Project(Qiankehe Platform Talent)GCC[2023]014Supported by the earmarked fund for GZMARS-Tea and Research on the Planting Technology of China HUANENG Photovoltaic Tea Garden(Project No.HNKJ2022-H135).
文摘The ATP-binding cassette(ABC)transporter is a gene superfamily in plants.ATP-binding cassette subfamily C(ABCC)protein is a multidrug resistance-associated(MRP)transporter.They play various roles in plant growth,development,and secondary metabolite transport.However,there are few studies on ABCC transporters in tea plants.In this study,genome-wide association study(GWAS)analysis of epigallocatechin gallate(EGCG)content in 108 strains of Kingbird revealed that CsABCCs may be involved in EGCG transport.We identified 25 CsABCC genes at the genomic level of the tea plant,their phylogenetic tree,gene structure,targeted miRNA and other bioinformatics were analyzed.The expression patterns of CsABCCs in eight different tissues and abiotic stress indicate that they have potential roles in regulating the growth,development,and defense of tea plants.The correlation analysis revealed that the expression of the CsABCC11 gene was closely related to the EGCG content in tea buds of 108 strains of the Kingbird,and the subcellular localization experiments in tobacco showed that CsABCC11 protein was localized on the plasma membrane.The virus-induced gene silencing(VIGS)strategy in tea plants further verified that CsABCC11 was involved in EGCG accumulation.Our study laid a foundation for studying the biological function of CsABCC and provided a new candidate molecular marker gene for further EGCG-related variety breeding,which will be of great interest to breeders.
基金Supported by Program of National Science and Technology Infra-structure (2005DKA21002-09)~~
文摘[Objective] The study aimed at analyzing the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.from the Pearl River Basin in Guangdong and Guangxi Provinces.[Method] Genetic diversity of 64 local varieties of Morus atropurpurea Roxb.was analyzed by ISSR molecular marker technique.The genetic relationship among these local varieties was researched by UPGMA method based on the genetic similarity coefficient.[Result] 128 bands were amplified from the total DNA of 64 local varieties using 13 ISSR primers,of which 109 bands accounting for 85.15% were polymorphic.It meant that there was rich genetic diversity among the local varieties tested.The genetic similarity coefficients among 64 local varieties were relatively high with a range of 0.500 0-0.929 7.In addition,64 local varieties were divided into two categories and the second could be further divided into 10 subcategories.It was suggested that the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.based on ISSR marker analysis has a certain correlation with geographical distribution.[Conclusion] ISSR marker technology was suitable for evaluating genetic relationship and genetic diversity of local varieties of Morus atropurpurea Roxb.in Pearl River Basin,and could provide scientific basis for DNA fingerprinting and identification of varieties of Morus atropurpurea Roxb.
文摘A participatory breeding on Arabica coffee involving farmers and plant breeders to select superior local varieties has been conducted at Lintong highland （North Sumatra）, Gayo highland （Central Aceh, Northern Sumatra） and Kendenan Plateau （Enrekang, South Sulawesi）. The aim of using this method was to find out superior varieties of Arabica coffee having appropriate specific traits and adaptable to such locations and accelerating the process of variety adoption by local farmers. Selection process was initiated by the farmer（s） based on high yielding performance by using their native experiences. The next step was conducted by plant breeder in collaboration with coffee farmers and other relevant scientists to evaluate more detail of cup quality, resistance to leaf rust and/or parasitic nematode as well as yielding potential and agronomic traits at different farmer＇s sites for several years observations. Research finding showed that three selected varieties namely Sigarar Utang, Gayo 1 and Gayo 2 had already been released by Minister of Agriculture for commercial planting at North Sumatera and Gayo highland. They performed excellent cup profile with high yielding ability （more than 1 t/ha） and tolerant to leaf rust disease. Therefore, it could support origin specialty coffee product at Gayo and Lintong highlands. However, observation over of selected local variety at Kendenan Plateau namely Salongge variety performed lower yielding ability （below 1 t/ha） and less stable yield over years as well as more heterogenous population in their offsprings than that of existing released varieties planted at the same location. Therefore, it could not be released as local varieties which adapted to specific location.
文摘The encapsulation in a nutritive matrix is an effective technique which allows the conservation of vitro-derived explants and protects their viability. The encapsulated propagules are generated by submerging explants in a natural polysaccharide solution of sodium alginate and calcium chloride allowing to obtain uniform capsules. In this work, we present preliminary results of a study on the effect of an encapsulation protocol on any local fruit varieties, conserved in a Regional in vitro germplasm bank.
文摘In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Sérédou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.
文摘This study explored the biodiversity in Local Thai rice Varieties （Oryza sativa L.） during May 2011 to March 2013 by conducting surveys and collecting rice varieties from 4 regions of Thailand. There are altogether 89 varieties of local rice which include 16 in Central region, 12 in Northern region, 23 in Northeastern region, and 38 in Southern region. Among them are of 2 types： 21 varieties of glutinous rice and 68 varieties of non-glutinous rice. Ecological classification suggested 72 varieties of lowland rice, 10 varieties of upland rice, and 7 varieties of floating rice. These varieties of rice were cultivated in the farmer fields of Nongbondaeng sub-district in Banbueng district of Chonburi province during the rainy season and off season between 2011 and 2013 and to capture their agricultural descriptors. Results revealed germination and seedling growth in 33 varieties. The Unknow 2 variety yields maximum weight of 6.47 grams per panicle, while Sor.6 Chumpae variety gives minimum weight of 0.85 grams per panicle. Aye Khong produces highest number of 317 filled grains per panicle, while the lowest is Sewkliang with 5 filled grains per panicle. Gumrai gives biggest size of seed of 0.47 × 1.01 mm, while Sangyod gives smallest size of 0.19 × 0.97 mm.
文摘In tomatoes,grafting onto resistant rootstocks represents an effective strategy to control several soil-borne diseases that reduce crop profitability,especially for landraceswith little or no resistance tomultiple pathogens/pests.In this study,the high-value‘Corbarino’tomato landrace was grafted onto seven commercial Solanum interspecific rootstocks to evaluate graft compatibility,yield performance,and qualitative characteristics under greenhouse healthy conditions.Three rootstocks were themost effective in improving fruit yield without negatively affecting the carpometric,technological,and health-related traits of the traditional tomato.‘Dinafort’rootstock increased fresh and dry yield,harvest index,and fruit/clusters,while mean fruit weight,shape index,total and soluble solid content,simple sugars,organic acids,flavonoids,ascorbic acid,and trans-lycopene content did not differ with respect to the ungrafted‘Corbarino’.‘Interpro’rootstock also showed promising results for the overall yield and quality traits,although it reduced the trans-lycopene content in the fruit.‘Silex’rootstock showed the highest harvest index as result of decreased vigour.The fruit quality induced by‘Silex’was satisfactory and high levels of simple sugars,flavonoids,ascorbic acid,and trans-lycopene were also observed.However,graft success,especially for‘Dinafort’and‘Silex’,needs to be improved by investigating more suitable methods for seedling production,grafting,acclimatization,etc.
基金Science and Technology Plan of Sichuan Province,China(2021YFYZ0001)Sichuan Beef Cattle Innovation Team of National Modern Agricultural Industrial Technology System(SCCXTD-2023-13)Special Project for Financial Operation of Sichuan Province,China。
文摘Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat use and formed through long-term natural selection and artificial selection.Because of the weak development and utilization of this breed,the economic benefits of excellent breeds have not been fully brought into play,and farmers'enthusiasm in breeding is poor,so that the number of Ebian spotted cattle has reduced year by year.In order to strengthen the protection,development and utilization of Ebian spotted cattle as a local excellent breed,combined with the third national survey of livestock and poultry genetic resources in 2021,Ebian spotted cattle was investigated,and a comprehensive,scientific and objective analysis of its population numbers was conducted.Besides,reasonable suggestions were put forward.
基金Supporting Service Delivery Systems of Irrigated Agriculture (TANRICE,2008–2012)
文摘In Tanzania, the phenology and seasonal variations of the yields of different rice cultivars have rarely been studied, especially under fully-irrigated conditions. A trial was conducted to identify the most suitable calendar for rice production in Tanzania under fully-irrigated conditions. Four popular rice cultivars, NERICA1, Wahiwahi, IR64 and TXD306, were transplanted monthly from January to December 2011. The four cultivars recorded similarly higher or lower yields than the annual means when transplanted in July （0.50-0.57 kg/m2） and April （0.07-0.31 kg/m2）. A yield-ranking analysis showed that plants transplanted in July was the most productive while those transplanted in April was the least productive, and also revealed a yield-seasonality for irrigated rice in Tanzania, a low-yield season （April-May）, a high-yield season （June-August）, and an unstable-yield season （September-March）. These yield seasons would appear to be closely linked to seasonal temperature variations. When transplanted in April-May, plants were exposed to very low temperatures between panicle initiation and flowering, apparently reducing yield through cold-induced sterility. Those transplanted in June-August prolonged their growth under relatively low temperatures and increased yield through increasing biomass production. In September- March, yield levels varied greatly due to the shortened phenological growth durations at higher temperatures. We conclude that under fully-irrigated conditions in Tanzania, rice should be transplanted in July to ensure the maximum production and yield stability. The yield-seasonality suggests that implementing measures to protect plants from low and high temperature stress at critical phenological stages may allow year-round rice production under fully-irrigated conditions in Tanzania.
文摘This study focused on the investigation of crop germplasm resources in coastal areas of Shandong Province, including 132 villages in 82 towns of 34 counties. The survey collected local varieties and wild resources of grain crops, economic crops, vegetables and fruit trees, and a total of 848 samples were collected, belonging to 54 species of 39 genera in 15 families. In this study, the current situation and growth and decline conditions of crop germplasm resources were investigated, and their botanical classification and utilization importance were analyzed. Furthermore, the conservation, development and utilization of crop germplasrp resources in coastal areas of Shandong Province were also discussed in this paper.
