Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant gen...Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant genotype） and 20078 （low light-sensitive genotype）, were used to study the effects of low light （photosynthetic photon flux density, PPFD was 75- 100 umol m-2 s-1, control 450-500 umol m-2 s-1） on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate （PN）, photosynthetic apparent quantum efficiency （Фi） and carboxylation efficiency （CE） of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point （LCP） decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II （Fv/Fm） was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance （ФPS II） was lower accompanied by an increased non-photochemical quenching （NPQ） in young and/or old leaves compared with mature leaves. The antenna thermal dissipation （D） was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy （Ex）. Compared with 20078, ShY could maintain higher PN, ФPS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.展开更多
Genetic diversity plays an essential role in plant breeding and utilization.Pepper is an important vegetable and spice crop worldwide.The genetic diversity of 1 904 accessions of pepper conserved at the National Mid-t...Genetic diversity plays an essential role in plant breeding and utilization.Pepper is an important vegetable and spice crop worldwide.The genetic diversity of 1 904 accessions of pepper conserved at the National Mid-term Genebank for Vegetables,Beijing,China was analyzed based on 29 simple sequence repeat(SSR)markers,which were evenly distributed over 12 pepper chromosomes.The pepper accessions were divided into two groups in a genetic structure analysis,and the two groups showed obvious differences in fruit type and geographical distribution.We finally selected 248 accessions capturing 75.6%of the SSR alleles as the core collection for further research.Insights into the genetic structure of pepper provide the basis for population-level gene mining and genetic improvement.展开更多
Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Thre...Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.展开更多
Pepper hybrid seeds production using male sterility could lower cost by reducing time and labour, and increase the genetic purity of the F1 seeds. To investigate the genetics of fertility restoration of the Peterson c...Pepper hybrid seeds production using male sterility could lower cost by reducing time and labour, and increase the genetic purity of the F1 seeds. To investigate the genetics of fertility restoration of the Peterson cytoplasmic sterility in pepper, a doubled haploid population of 115 pepper lines obtained from anther culture of the F1 hybrid between Yolo Wonder （sterility maintainer line） and Perennial （fertility restorer line） and the parental lines were test-crossed by 77013A （a strict cytoplasmic-genic male sterile line）. The fertility of the test-crossed lines was assessed in greenhouse and open field with the following three criteria： pollen index （PI, visual estimation of pollen amount per flower）, pollen number （PN, pollen counting under microscope）, and seed number （SN, the number of seeds per fruit in open pollination）. Correlations between the each couple of criteria within, as well as between the cultivation methods ranged from 0.55 to 0.84. Analysis of variance showed that the genotype （DH line） and environment were the significant sources of variation of the fertility. Narrow sense of heritance of fertility restoration ranged from 0.38 to 0.92, depending on the criteria and environment. The distribution of the progeny was continuous between the parental genotypes indicating the quantitative inheritance of fertility restoration. Inferred from segregation according to Snape et al.（1984）, the number of segregating genes was estimated to be that three to four genetic factors were involved in pollen traits （PI and PN） and five to eight genetic factors in seed production （SN）. The heredity analysis of the CMS will be helpful for understanding of the genetic mechanism of the fertility restoration and the exploitation of the CMS in hybrid seed production.展开更多
Pepper（Capsicum spp.） is an important vegetable crop in the world. Now the pepper in China contributes one-third of the world＇s peppers production. Genetic diversity of the pepper germplasm of China is expected int...Pepper（Capsicum spp.） is an important vegetable crop in the world. Now the pepper in China contributes one-third of the world＇s peppers production. Genetic diversity of the pepper germplasm of China is expected interesting to know. To explore the structure of genetic diversity in Chinese pepper germplasm resources and possible relationship with cultivar types or geographic origin, we sampled and compared 372 Gen Bank pepper accessions（local cultivars and landraces） from 31 provinces, autonomous regions and municipalities of China and 31 additional accessions from other countries. These accessions were genotyped using 28 simple sequence repeat（SSR） markers spanning the entire pepper genome. We then investigated the genetic structure of the sampled collection using model-based analysis in STRUCTURE v2.3.4 and examined genetic relationships by the unweighted pair-group method of mathematical averages（UPGMA） in MEGA. In addition to geographic origin, we evaluated eight plant and fruit traits. In total, 363 alleles were amplified using the 28 SSR primers. Gene diversity, polymorphism information content and heterozygosity of the 28 SSR loci were estimated as 0.09–0.92, 0.08–0.92 and 0.01–0.34, respectively. The UPGMA cluster analysis clearly distinguished Capsicum annuum L. from other cultivated pepper species. Population structure analysis of the 368 C. annuum accessions uncovered three genetic groups which also corresponded to distinct cultivar types with respect to the plant and fruit descriptors. The genetic structure was also related to the geographic origin of the landraces. Overall results indicate that genetic diversity of Chinese pepper landraces were structured by migration of genotypes followed by human selection for cultivar types in agreement with consumption modes and adaptation to the highly diversified agro-climatic conditions.展开更多
基金supported by the National Science and Technology Support Program, China (2011BAZ01732-2)the Earmarked Fund for Modern Agro-Industry Technology Research System in China (CARS-25-A-07)
文摘Low light stress is one of the main limiting factors which influence the production of sweet pepper under protected cultivation in China. In this experiment, two genotypes of sweet pepper, ShY （low light-tolerant genotype） and 20078 （low light-sensitive genotype）, were used to study the effects of low light （photosynthetic photon flux density, PPFD was 75- 100 umol m-2 s-1, control 450-500 umol m-2 s-1） on photosynthesis during leaf development. The result indicated that under low light chlorophyll content, net photosynthetic rate （PN）, photosynthetic apparent quantum efficiency （Фi） and carboxylation efficiency （CE） of sweet pepper leaves increased gradually and decreased after reaching the maximum levels. The time to reach the peak values for all the above parameters was delayed, whereas the light compensation point （LCP） decreased gradually along with leaf expansion. The decrease in maximum quantum yield of PS II （Fv/Fm） was not observed at any stages of the leaf development under low light condition, but the actual PS II efficiency under irradiance （ФPS II） was lower accompanied by an increased non-photochemical quenching （NPQ） in young and/or old leaves compared with mature leaves. The antenna thermal dissipation （D） was a main way of heat dissipation when young leaves received excessive light energy, while the decline in photosynthetic function in senescence leaf was mostly owing to the decrease in carbon assimilation capacity, followed by a significantly increased allocation of excessive energy （Ex）. Compared with 20078, ShY could maintain higher PN, ФPS II and lower QA reduction state for a longer time during leaf development. Thus, in ShY photosynthetic efficiency and the activity of electron transport of PS II were not significantly affected due to low light stress.
基金funded by the National Key Technology Research and Development Program of China (2016YFD0100200 and 2016YFD0101700)the earmarked fund for China Agriculture Research System (CARS-25 and CARS-24-A-01)+1 种基金the Core Research Budget of the Non-profit Governmental Research Institute, Chinese Academy of Agricultural Sciences (1610032011011)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIPIVFCAAS)
文摘Genetic diversity plays an essential role in plant breeding and utilization.Pepper is an important vegetable and spice crop worldwide.The genetic diversity of 1 904 accessions of pepper conserved at the National Mid-term Genebank for Vegetables,Beijing,China was analyzed based on 29 simple sequence repeat(SSR)markers,which were evenly distributed over 12 pepper chromosomes.The pepper accessions were divided into two groups in a genetic structure analysis,and the two groups showed obvious differences in fruit type and geographical distribution.We finally selected 248 accessions capturing 75.6%of the SSR alleles as the core collection for further research.Insights into the genetic structure of pepper provide the basis for population-level gene mining and genetic improvement.
基金supported by the National Key Technology R&D Program of China (2011BAZ01732)Project of Ministry of Agriculture of China (CARS-25)+1 种基金the National High-Tech R&D Program of China (863 Program, 2012AA100103002)Core Research Budget of the Non-profit Governmental Research Institute, China (ICS, CAAS, 1610032011011)
文摘Fruit set and development are affected by many phytohormones, including gibberellin. Little is known regarding molecular mechanism underlying gibberellin mediated fruit set and development especially in Capsicum. Three gibberellin recep- tors, CaGIDlb.1, CaGIDlb.2 and CaGIDlc, and a DELLA protein, CaGAI, have been identified in Capsicum annuum L. During the fruit development, the expression level of CaGIDlc was low, and the expression fold change is mild. However, CaGIDlb. 1 and CaGIDlb.2 were relatively higher and more acute, which indicates that CaGIDlb. 1 and CaGID1b.2 may play an important role in fruit pericarp, placenta and seed. Ectopic expressions of CaGIDlb. 1, CaGIDlb.2 and CaGIDlc in Arabidopsis double mutant gidla gidlc increased plant height, among which CaGIDlb.2 had the most significant effect; CaGAI reduced plant height in double mutant rga-24/gai-t6, having a similar function to AtGID1 and AtGAI in stem elon- gation. Yeast two-hybrid （Y2H） and bimolecular fluorescence complementation （BiFC） assays indicated that CaGIDlb.1 and CaGID1 b.2 interact with CaGAI in a GA-dependent manner, while CaGIDlc interacts with CaGAI in a GA-independent manner. Our study reveals the key elements during gibberellin signaling in Capsicum and supports the critical importance of gibberellin for Capsicum fruit set and development.
基金The study was funded by the National 863 Program, China （2002AA207012-1-3, 2001AA241121-9）the National Natural Science Foundation of China （3980453）.
文摘Pepper hybrid seeds production using male sterility could lower cost by reducing time and labour, and increase the genetic purity of the F1 seeds. To investigate the genetics of fertility restoration of the Peterson cytoplasmic sterility in pepper, a doubled haploid population of 115 pepper lines obtained from anther culture of the F1 hybrid between Yolo Wonder （sterility maintainer line） and Perennial （fertility restorer line） and the parental lines were test-crossed by 77013A （a strict cytoplasmic-genic male sterile line）. The fertility of the test-crossed lines was assessed in greenhouse and open field with the following three criteria： pollen index （PI, visual estimation of pollen amount per flower）, pollen number （PN, pollen counting under microscope）, and seed number （SN, the number of seeds per fruit in open pollination）. Correlations between the each couple of criteria within, as well as between the cultivation methods ranged from 0.55 to 0.84. Analysis of variance showed that the genotype （DH line） and environment were the significant sources of variation of the fertility. Narrow sense of heritance of fertility restoration ranged from 0.38 to 0.92, depending on the criteria and environment. The distribution of the progeny was continuous between the parental genotypes indicating the quantitative inheritance of fertility restoration. Inferred from segregation according to Snape et al.（1984）, the number of segregating genes was estimated to be that three to four genetic factors were involved in pollen traits （PI and PN） and five to eight genetic factors in seed production （SN）. The heredity analysis of the CMS will be helpful for understanding of the genetic mechanism of the fertility restoration and the exploitation of the CMS in hybrid seed production.
基金supported by the National Key Technology Research and Development Program of China(2011BAZ01732)the Project of the Ministry of Agriculture of China(CARS-25)+2 种基金the Core Research Budget of the Non-profit Governmental Research Institute,China(ICS,CAAS1610032011011)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)
文摘Pepper（Capsicum spp.） is an important vegetable crop in the world. Now the pepper in China contributes one-third of the world＇s peppers production. Genetic diversity of the pepper germplasm of China is expected interesting to know. To explore the structure of genetic diversity in Chinese pepper germplasm resources and possible relationship with cultivar types or geographic origin, we sampled and compared 372 Gen Bank pepper accessions（local cultivars and landraces） from 31 provinces, autonomous regions and municipalities of China and 31 additional accessions from other countries. These accessions were genotyped using 28 simple sequence repeat（SSR） markers spanning the entire pepper genome. We then investigated the genetic structure of the sampled collection using model-based analysis in STRUCTURE v2.3.4 and examined genetic relationships by the unweighted pair-group method of mathematical averages（UPGMA） in MEGA. In addition to geographic origin, we evaluated eight plant and fruit traits. In total, 363 alleles were amplified using the 28 SSR primers. Gene diversity, polymorphism information content and heterozygosity of the 28 SSR loci were estimated as 0.09–0.92, 0.08–0.92 and 0.01–0.34, respectively. The UPGMA cluster analysis clearly distinguished Capsicum annuum L. from other cultivated pepper species. Population structure analysis of the 368 C. annuum accessions uncovered three genetic groups which also corresponded to distinct cultivar types with respect to the plant and fruit descriptors. The genetic structure was also related to the geographic origin of the landraces. Overall results indicate that genetic diversity of Chinese pepper landraces were structured by migration of genotypes followed by human selection for cultivar types in agreement with consumption modes and adaptation to the highly diversified agro-climatic conditions.
