Seed vigor is an index of seed quality that is used to describe the rapid and uniform germination and the establish- ment of strong seedlings in any environmental conditions. Strong seed vigor in low-temperature germi...Seed vigor is an index of seed quality that is used to describe the rapid and uniform germination and the establish- ment of strong seedlings in any environmental conditions. Strong seed vigor in low-temperature germination conditions is particularly important in direct-sowing rice production systems. However, seed vigor has not been selected as an important breeding trait in traditional breeding programs due to its quantitative inherence. In this study, we identified and mapped eight quantitative trait loci （QTLs） for seed vigor by using a recombinant inbred population from a cross between rice （Oryza sativa L. ssp. indica） cultivars ZS97 and MH63. Conditional QTL analysis identified qSV-1, qSV-Sb, qSV-6a, qSV- 6b, and qSV-11 influenced seedling establishment and that qSV- 5a, qSV-Sc, and qSV-8 influenced only germination. Of these, qSV-1, qSV-Sb, qSV-6a, qSV-6b, and qSV-8 were low-tempera- ture-specific QTLs. Two major-effective QTLs, qSV-1, and qSV-5cwere narrowed down to 1.13-Mbp and 4oo-kbp genomic regions, respectively. The results provide tightly linked DNA markers for the marker-assistant pyramiding of multiple positive alleles for increased low-temperature germination seed vigor in both normal and environments.展开更多
The six years walnut（Juglans regia）cultivars （grafting plant） and three years seedlings were used as material to study the change of the endogenous hormone contents in roots and buds and the correlation with growt...The six years walnut（Juglans regia）cultivars （grafting plant） and three years seedlings were used as material to study the change of the endogenous hormone contents in roots and buds and the correlation with growth vigor of walnut in the same year. The results indicated that the endogenous hormone contents in bud of different walnut cultivars had insignificant correlation with the growth vigor. The GA3 content in roots of walnut seedlings had positive significant correlation with tree height and its increment. The ABA content in roots of walnut seedlings had strikingly negative relationship with tree height and its increment, and trunk girth. The GA3 content in buds of walnut seedlings had positive correlation significantly with the increment of tree height and the ABA content in buds of walnut seedling had strikingly negative relationship with tree height and its increment. The IAA content in roots of walnut seedlings had bally positive correlation significantly with that in buds.展开更多
Abstract: In a laboratory study, indica and japonica rice (Oryza sativa L.) seeds were exposed to thermal hardening (heating followed by chilling followed by heating; chilling followed by heating followed by chilling;...Abstract: In a laboratory study, indica and japonica rice (Oryza sativa L.) seeds were exposed to thermal hardening (heating followed by chilling followed by heating; chilling followed by heating followed by chilling; heating followed by chilling or chilling followed by heating). In indica rice, heating followed by chilling followed by heating resulted in decreased mean germination time, time to start germination, electrical conductivity of seed leachates, and time to 50% germination, as well as increased germination index, energy of germination, radicle and plumule length, root length, root/shoot ratio, root fresh and dry weight, radicle and plumule growth rate, and shoot fresh weight. In japonica rice, chilling followed by heating followed by chilling performed better than all other treatments, including control.展开更多
基金supported in part by the National High Technology Research and Development Program of China (2012AA10A304)
文摘Seed vigor is an index of seed quality that is used to describe the rapid and uniform germination and the establish- ment of strong seedlings in any environmental conditions. Strong seed vigor in low-temperature germination conditions is particularly important in direct-sowing rice production systems. However, seed vigor has not been selected as an important breeding trait in traditional breeding programs due to its quantitative inherence. In this study, we identified and mapped eight quantitative trait loci （QTLs） for seed vigor by using a recombinant inbred population from a cross between rice （Oryza sativa L. ssp. indica） cultivars ZS97 and MH63. Conditional QTL analysis identified qSV-1, qSV-Sb, qSV-6a, qSV- 6b, and qSV-11 influenced seedling establishment and that qSV- 5a, qSV-Sc, and qSV-8 influenced only germination. Of these, qSV-1, qSV-Sb, qSV-6a, qSV-6b, and qSV-8 were low-tempera- ture-specific QTLs. Two major-effective QTLs, qSV-1, and qSV-5cwere narrowed down to 1.13-Mbp and 4oo-kbp genomic regions, respectively. The results provide tightly linked DNA markers for the marker-assistant pyramiding of multiple positive alleles for increased low-temperature germination seed vigor in both normal and environments.
文摘The six years walnut（Juglans regia）cultivars （grafting plant） and three years seedlings were used as material to study the change of the endogenous hormone contents in roots and buds and the correlation with growth vigor of walnut in the same year. The results indicated that the endogenous hormone contents in bud of different walnut cultivars had insignificant correlation with the growth vigor. The GA3 content in roots of walnut seedlings had positive significant correlation with tree height and its increment. The ABA content in roots of walnut seedlings had strikingly negative relationship with tree height and its increment, and trunk girth. The GA3 content in buds of walnut seedlings had positive correlation significantly with the increment of tree height and the ABA content in buds of walnut seedling had strikingly negative relationship with tree height and its increment. The IAA content in roots of walnut seedlings had bally positive correlation significantly with that in buds.
文摘Abstract: In a laboratory study, indica and japonica rice (Oryza sativa L.) seeds were exposed to thermal hardening (heating followed by chilling followed by heating; chilling followed by heating followed by chilling; heating followed by chilling or chilling followed by heating). In indica rice, heating followed by chilling followed by heating resulted in decreased mean germination time, time to start germination, electrical conductivity of seed leachates, and time to 50% germination, as well as increased germination index, energy of germination, radicle and plumule length, root length, root/shoot ratio, root fresh and dry weight, radicle and plumule growth rate, and shoot fresh weight. In japonica rice, chilling followed by heating followed by chilling performed better than all other treatments, including control.
