Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the gr...Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the grain is considered the most cost-effective approach to alleviate malnutrition. Development of molecular markers for high grain concentrations of essential elements, particularly Zn, for use in marker-assisted selection (MAS) can hasten breeding efforts to develop rice varieties with nutrient-dense grain. We performed QTL mapping for four agronomic traits: days to 50% flowering, plant height, number of tillers, grain yield, and 13 grain elements: As, B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn, in two doubled-haploid populations derived from the crosses IR64 × IR69428 and BR29 × IR75862. These populations were phenotyped during 2015DS and 2015WS at IRRI, Los Ba os, The Philippines, and genotyped them with a 6 K SNP chip. Inclusive composite interval mapping revealed 15 QTL for agronomic traits and 50 QTL for grain element concentration. Of these, eight QTL showed phenotypic variance of >25% and 11 QTL were consistent across seasons. There were seven QTL co-localization regions containing QTL for more than two traits. Twenty five epistatic interactions were detected for two agronomic traits and seven mineral elements. Several DH lines with high Fe and Zn in polished rice were identified. These lines can be used as donors for breeding high-Zn rice varieties. Some of the major QTL can be further validated and used in MAS to improve the concentrations of nutritive elements in rice grain.展开更多
Aluminum(Al)toxicity in acid soils is a significant limitation to crop production worldwide,as 13%of the world's rice is produced in acid soil with high Al content.Rice is likely the most Al-resistant cereal and a...Aluminum(Al)toxicity in acid soils is a significant limitation to crop production worldwide,as 13%of the world's rice is produced in acid soil with high Al content.Rice is likely the most Al-resistant cereal and also the cereal,where Al resistance is the most genetically complex with external detoxification and internal tolerance.Many Al-resistance genes in rice have been cloned,including Al resistance transcription factor 1(ART1)and other transcription factors,organic acid transporter genes,and metal ion transporter gene.This review summarized the recent characterized genes affecting Al tolerance in rice and the interrelationships between Al and other plant nutrients.展开更多
Amylose content(AC)is the key determinant of eating and cooking quality(ECQ)of rice.The major Wxa allele of granule-bound starch synthase I(GBSS I)in indica rice produces higher AC,making rice hard and dry after cooki...Amylose content(AC)is the key determinant of eating and cooking quality(ECQ)of rice.The major Wxa allele of granule-bound starch synthase I(GBSS I)in indica rice produces higher AC,making rice hard and dry after cooking.Recent work has improved ECQ of japonica rice via clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)or cytosine base editing(CBE)techniques.展开更多
A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling indust...A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling industry and to identify enablers and barriers to its growth in Nepal. Coarse rice varieties dominate Nepal’s rice processing industry, with a 42% share by total weight, followed by medium rice (34%) and fine varieties (less than 7%). Polished white rice (<em>Arwa</em>) was the dominant rice type in Nepal in the survey, followed by parboiled and steamed rice. The price and profit margins increased from coarse to fine rice varieties and from <em>Arwa</em> to parboiled and steamed rice. The cost of milling also followed a similar trend. The rice milling industry in Nepal largely influences the adoption or non-adoption of any specific type of rice variety by dictating specific brands in the market and this has important implications for rice research and development. The rice processing industry of Nepal was unable to compete with the Indian rice milling industry because of: 1) low profit margins due to the high cost of rice production and procurement, 2) a lack of economies of scale, 3) a lack of milling technologies for long and extra-long and steamed rice in the country and a lack of investment to modernize rice milling technology, and 4) unavailability of paddy throughout the year locally. Millers were willing to upgrade their rice milling technology to include high throughput parboiling, steamed rice as well as long and extra-long grain rice. This will be a strategic decision in counteracting the ever-increasing rice imports in Nepal. We believe that the findings of the study will be vital for formulating an appropriate rice research, development and rice processing strategy for Nepal to achieve food and nutritional security and the Sustainable Development Goals.展开更多
Cadmium(Cd)is a non-essential toxic metal that is harmful to plants.To investigate the genetic mechanism of Cd tolerance in rice,quantitative trait loci(QTLs)associated with Cd tolerance at the seedling stage were ana...Cadmium(Cd)is a non-essential toxic metal that is harmful to plants.To investigate the genetic mechanism of Cd tolerance in rice,quantitative trait loci(QTLs)associated with Cd tolerance at the seedling stage were analyzed using a recombinant inbred line(RIL)population derived from a cross between PA64s and 93-11.A total of 36 QTLs associated with shoot length,root length,shoot dry weight,root dry weight and total dry weight were detected in Hangzhou and Lingshui of China.Among them,15 QTLs were identified under the control condition and 15 QTLs were identified under the Cd stress condition,and 6 QTLs for Cd tolerant coefficient were detected on chromosomes 1,3,7 and 9.The qCDSL1.1 and qCDSL1.2 were identified in Hangzhou and Lingshui,respectively,and had overlapping intervals on chromosome 1.To further confirm the effects of qCDSL1.1 and qCDSL1.2,we developed a chromosome segment substitution line(CSSL),CSSLqCDSL1,in 93-11 background harboring qCDSL1.1/qCDSL1.2 from PA64s.Compared to 93-11,CSSLqCDSL1 had increased shoot length under the Cd stress condition.These results pave the way for further isolation of those genes controlling Cd tolerance in rice and marker-assistant selection of rice elite varieties with Cd tolerance.展开更多
基金HarvestPlus for funding development of high Zinc rice
文摘Malnutrition is one of the prevailing health problems worldwide, affecting a large proportion of the populations in rice-consuming countries. Breeding rice varieties with increased concentrations of elements in the grain is considered the most cost-effective approach to alleviate malnutrition. Development of molecular markers for high grain concentrations of essential elements, particularly Zn, for use in marker-assisted selection (MAS) can hasten breeding efforts to develop rice varieties with nutrient-dense grain. We performed QTL mapping for four agronomic traits: days to 50% flowering, plant height, number of tillers, grain yield, and 13 grain elements: As, B, Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, P, and Zn, in two doubled-haploid populations derived from the crosses IR64 × IR69428 and BR29 × IR75862. These populations were phenotyped during 2015DS and 2015WS at IRRI, Los Ba os, The Philippines, and genotyped them with a 6 K SNP chip. Inclusive composite interval mapping revealed 15 QTL for agronomic traits and 50 QTL for grain element concentration. Of these, eight QTL showed phenotypic variance of >25% and 11 QTL were consistent across seasons. There were seven QTL co-localization regions containing QTL for more than two traits. Twenty five epistatic interactions were detected for two agronomic traits and seven mineral elements. Several DH lines with high Fe and Zn in polished rice were identified. These lines can be used as donors for breeding high-Zn rice varieties. Some of the major QTL can be further validated and used in MAS to improve the concentrations of nutritive elements in rice grain.
基金This research was financially supported by the National Natural Science Foundation of China(Grant No.31902103)the Dapeng District Industry Development Special Funds(Grant No.KY20180218)the Shenzhen Science and Technology Projects(Grant No.JSGG20160608160725473)in China.
文摘Aluminum(Al)toxicity in acid soils is a significant limitation to crop production worldwide,as 13%of the world's rice is produced in acid soil with high Al content.Rice is likely the most Al-resistant cereal and also the cereal,where Al resistance is the most genetically complex with external detoxification and internal tolerance.Many Al-resistance genes in rice have been cloned,including Al resistance transcription factor 1(ART1)and other transcription factors,organic acid transporter genes,and metal ion transporter gene.This review summarized the recent characterized genes affecting Al tolerance in rice and the interrelationships between Al and other plant nutrients.
基金supported by the China National Key Research and Development Program(Grant No.2020YFE0202300)the Central Public-Interest Scientific Institution Basal Research Fund of China(Grant No&Y2020PT07 and Y2020YJ09)the International Science&Technology Innovation Program of Chinese Academy of Agricultural Sciences,China(Grant No.CAAS-ZDRW202109).
文摘Amylose content(AC)is the key determinant of eating and cooking quality(ECQ)of rice.The major Wxa allele of granule-bound starch synthase I(GBSS I)in indica rice produces higher AC,making rice hard and dry after cooking.Recent work has improved ECQ of japonica rice via clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)or cytosine base editing(CBE)techniques.
文摘A rice mill survey covering diverse rice processing companies in terms of their milling output, type of technology and year of establishment was conducted to understand the current situation of the rice milling industry and to identify enablers and barriers to its growth in Nepal. Coarse rice varieties dominate Nepal’s rice processing industry, with a 42% share by total weight, followed by medium rice (34%) and fine varieties (less than 7%). Polished white rice (<em>Arwa</em>) was the dominant rice type in Nepal in the survey, followed by parboiled and steamed rice. The price and profit margins increased from coarse to fine rice varieties and from <em>Arwa</em> to parboiled and steamed rice. The cost of milling also followed a similar trend. The rice milling industry in Nepal largely influences the adoption or non-adoption of any specific type of rice variety by dictating specific brands in the market and this has important implications for rice research and development. The rice processing industry of Nepal was unable to compete with the Indian rice milling industry because of: 1) low profit margins due to the high cost of rice production and procurement, 2) a lack of economies of scale, 3) a lack of milling technologies for long and extra-long and steamed rice in the country and a lack of investment to modernize rice milling technology, and 4) unavailability of paddy throughout the year locally. Millers were willing to upgrade their rice milling technology to include high throughput parboiling, steamed rice as well as long and extra-long grain rice. This will be a strategic decision in counteracting the ever-increasing rice imports in Nepal. We believe that the findings of the study will be vital for formulating an appropriate rice research, development and rice processing strategy for Nepal to achieve food and nutritional security and the Sustainable Development Goals.
基金the National Natural Science Foundation of China(Grant No.31671761)the Agricultural Science and Technology Innovation Program,Shenzhen Science and Technology Program(Grant No.2017050414212249).
文摘Cadmium(Cd)is a non-essential toxic metal that is harmful to plants.To investigate the genetic mechanism of Cd tolerance in rice,quantitative trait loci(QTLs)associated with Cd tolerance at the seedling stage were analyzed using a recombinant inbred line(RIL)population derived from a cross between PA64s and 93-11.A total of 36 QTLs associated with shoot length,root length,shoot dry weight,root dry weight and total dry weight were detected in Hangzhou and Lingshui of China.Among them,15 QTLs were identified under the control condition and 15 QTLs were identified under the Cd stress condition,and 6 QTLs for Cd tolerant coefficient were detected on chromosomes 1,3,7 and 9.The qCDSL1.1 and qCDSL1.2 were identified in Hangzhou and Lingshui,respectively,and had overlapping intervals on chromosome 1.To further confirm the effects of qCDSL1.1 and qCDSL1.2,we developed a chromosome segment substitution line(CSSL),CSSLqCDSL1,in 93-11 background harboring qCDSL1.1/qCDSL1.2 from PA64s.Compared to 93-11,CSSLqCDSL1 had increased shoot length under the Cd stress condition.These results pave the way for further isolation of those genes controlling Cd tolerance in rice and marker-assistant selection of rice elite varieties with Cd tolerance.
