不同基因型杂交水稻根系分布特征及其对水稻耐旱能力的影响

Root distribution characteristics of hybrid rice with different genotypes and their effects on drought tolerance of rice

干旱是限制水稻产量的主要因素之一.以46个杂交水稻品种为材料,采用人工旱棚和盆栽试验,通过研究不同水稻品种在干旱条件下的根系分布、相关酶活性及DRO1基因测序,分析了不同品种水稻根系分布特征及其对水稻苗期抗旱能力的影响.结果表明:(1)依据综合耐旱指数值,可以将46个杂交水稻品种分为三类:耐旱性品种(综合耐旱指数≥0.75)、半耐旱性品种(综合耐旱指数≥0.65)和干旱敏感性品种(综合耐旱指数≤0.65).(2)耐旱品种川谷优208和德优4727在30~50 cm土层的根长、根数和根重显著增加,在干旱胁迫期间根系中的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著提高.(3)DRO1基因测序表明,耐旱性、干旱敏感性品种在第3外显子区均表现出单核苷酸多态性;同时相关性分析表明,DRO1基因不仅与根系分布有较高的相关性,而且与SOD和POD活性也有较高的相关性.深根系作为耐旱水稻品种的重要特性,对水稻抗旱能力起着至关重要的作用.根系数量、根系重量、根系POD和SOD活性以及DRO1基因性状等可作为季节性干旱地区耐旱水稻品种筛选的重要指标.

Drought is one of the main factors limiting rice yield.Using 46 hybrid rice varieties as experimental materials,artificial dry-shed experiment and pot experiment were carried out to study the root distribution,related enzyme activities and DRO1 gene sequencing of different rice varieties under drought condition The root distribution characteristics of different rice genotypes and their effects on drought resistance at seedling stage were analyzed.The results show that:(1)according to the CTIRDE value,can divide 46 hybrid rice varieties into three categories:drought-tolerant(CTIRDE value≥0.75),semi-drought-tolerant(CTIRDE value≥0.65)and drought-sensitive(CTIRDE value≤0.65).(2)The root length,root number and root weight of drought tolerant varieties Chuanguyou 208 and Deyou 4727 increased significantly in 30-50 cm soil layer,and the root Superoxide dismutase and root Peroxidase activity increased significantly during drought stress.(3)DRO1 showed SNP in Exon 3 of drought-tolerant and drought-sensitive cultivars,and DRO1 was highly correlated not only with root distribution but also with SOD and POD activities.As an important character of drought-tolerant rice varieties,deep root system plays an important role in drought-resistant ability of rice.Traits such as root number,root weight,root Peroxidase and Superoxide dismutase activity,and DRO1 gene could be used to screen drought tolerant rice in seasonal arid areas.