Plant height （PH） is one of the most important agronomic traits of rice, as it directly affects the lodging resistance and the high yield potential. Meanwhile, PH is often constrained by water supply over the entire...Plant height （PH） is one of the most important agronomic traits of rice, as it directly affects the lodging resistance and the high yield potential. Meanwhile, PH is often constrained by water supply over the entire growth period. In this study, a recombinant inbred line （RIL） derived from Xiaobaijingzi and Kongyu 131 strains grown under drought stress and with normal irrigation over 2 yr （2013 and 2014）, respectively （regarded as four environments）, was used to dissect the genetic basis of PH by developmental dynamics QTL analysis combined with QTL^environment interactions. QTLs with net effects excluding the accumulated effects were detected to explore the relationship between genexgene interactions and genexenvironment interactions in specific growth period. A total of 26 additive QTLs （A-QTLs） and 37 epistatic QTLs （E-QTLs） associated with PH were detected by unconditional and conditional mapping over seven growth periods, qPH-2-3, qPH-4-3, qPH-6-1, qPH-7-1, and qPH-12-5 could be detected by both unconditional and conditional analyses, qPH-4-3 and qPH-7-5 were detected in four stages （periods） to be sequentially expressed QTLs controlling PH continuous variation. QTLs with additive effects （A-QTLs） were mostly expressed in the period $3iS2 （the time interval from stages 2 to 3）, and QTLxenvironment interactions performed actively in the first three stages （periods） which could be an important developmental period for rice to undergo external morphogenesis during drought stress. Several QTLs showed high adaptability for drought stress and many QTLs were closely related to the environments such as qPH-3-5, qPH-2-2 and qPH-6-1. 72.5% of the QTLs with a and aa effects detected by conditional analysis were under drought stress, and the PVE of QTLs detected by conditional analysis under drought stress were also much higher than that under normal irrigation. We infer that environments would influence the detection results and sequential expression of genes was highly influenced by environments as well. Many QTLs （qPH-1-2, qPH-3-5, qPH-4-1, qPH-2-3） coincident with previously identified drought resistance genes. The result of this study is helpful to elucidating the genetic mechanism and regulatory network underlying the development of PH in rice and providing references to marker assisted selection.展开更多
To explore the germination mechanism of salt-stressed rice improved by exogenous proline, and provide a theoretical basis to rice direct sowing technology for salinized soil, the effects of soaking with proline on ger...To explore the germination mechanism of salt-stressed rice improved by exogenous proline, and provide a theoretical basis to rice direct sowing technology for salinized soil, the effects of soaking with proline on germination status, amylase activity and isoenzyme were studied in this paper. The results showed that germination status including germination energy（GE）, germination rate（GR）, relative germination energy（RGE） and relative germination rate（RGR） significantly decreased as the same as the activities of alpha-amylase, beta-amylase and the total amylase under salt stress. Soaking with exogenous proline improved the germination status of rice under salt stress. Moreover, GE and RGE of salt-stressed rice were improved with increasing of proline concentration at the range of 5-45 mmol ·L-1. Soaking with 15 mmol ·L-1 and 30 mmol ·L-1 proline significantly improved the amylase activities（e.g. alpha-amylase, beta-amylase and total amylase） of rice under salt stress. Salt stress inhibited the express of beta-amylase isoenzyme temporarily, but had few impacts on alpha-amylase isozyme. Soaking with 30 mmol ·L-1 proline brightened District I and increased the width of ＇i＇ brand in District II of alpha-amylase isoenzyme, but had few impacts on beta-amylase isoenzyme. In a word, soaking with proline could effectively alleviate the inhibitory effects of salt stress on seed germination.展开更多
基金supported by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2013BAD20B04)
文摘Plant height （PH） is one of the most important agronomic traits of rice, as it directly affects the lodging resistance and the high yield potential. Meanwhile, PH is often constrained by water supply over the entire growth period. In this study, a recombinant inbred line （RIL） derived from Xiaobaijingzi and Kongyu 131 strains grown under drought stress and with normal irrigation over 2 yr （2013 and 2014）, respectively （regarded as four environments）, was used to dissect the genetic basis of PH by developmental dynamics QTL analysis combined with QTL^environment interactions. QTLs with net effects excluding the accumulated effects were detected to explore the relationship between genexgene interactions and genexenvironment interactions in specific growth period. A total of 26 additive QTLs （A-QTLs） and 37 epistatic QTLs （E-QTLs） associated with PH were detected by unconditional and conditional mapping over seven growth periods, qPH-2-3, qPH-4-3, qPH-6-1, qPH-7-1, and qPH-12-5 could be detected by both unconditional and conditional analyses, qPH-4-3 and qPH-7-5 were detected in four stages （periods） to be sequentially expressed QTLs controlling PH continuous variation. QTLs with additive effects （A-QTLs） were mostly expressed in the period $3iS2 （the time interval from stages 2 to 3）, and QTLxenvironment interactions performed actively in the first three stages （periods） which could be an important developmental period for rice to undergo external morphogenesis during drought stress. Several QTLs showed high adaptability for drought stress and many QTLs were closely related to the environments such as qPH-3-5, qPH-2-2 and qPH-6-1. 72.5% of the QTLs with a and aa effects detected by conditional analysis were under drought stress, and the PVE of QTLs detected by conditional analysis under drought stress were also much higher than that under normal irrigation. We infer that environments would influence the detection results and sequential expression of genes was highly influenced by environments as well. Many QTLs （qPH-1-2, qPH-3-5, qPH-4-1, qPH-2-3） coincident with previously identified drought resistance genes. The result of this study is helpful to elucidating the genetic mechanism and regulatory network underlying the development of PH in rice and providing references to marker assisted selection.
基金Supported by the Project of Twelfth Five-year Plan for Sci & Tech Research of China in Rural Areas(2011BAD35B02-01)Program of Sci & Tech Research of China(2011BAD16B11)
文摘To explore the germination mechanism of salt-stressed rice improved by exogenous proline, and provide a theoretical basis to rice direct sowing technology for salinized soil, the effects of soaking with proline on germination status, amylase activity and isoenzyme were studied in this paper. The results showed that germination status including germination energy（GE）, germination rate（GR）, relative germination energy（RGE） and relative germination rate（RGR） significantly decreased as the same as the activities of alpha-amylase, beta-amylase and the total amylase under salt stress. Soaking with exogenous proline improved the germination status of rice under salt stress. Moreover, GE and RGE of salt-stressed rice were improved with increasing of proline concentration at the range of 5-45 mmol ·L-1. Soaking with 15 mmol ·L-1 and 30 mmol ·L-1 proline significantly improved the amylase activities（e.g. alpha-amylase, beta-amylase and total amylase） of rice under salt stress. Salt stress inhibited the express of beta-amylase isoenzyme temporarily, but had few impacts on alpha-amylase isozyme. Soaking with 30 mmol ·L-1 proline brightened District I and increased the width of ＇i＇ brand in District II of alpha-amylase isoenzyme, but had few impacts on beta-amylase isoenzyme. In a word, soaking with proline could effectively alleviate the inhibitory effects of salt stress on seed germination.
