水稻资源全生育期耐盐性鉴定筛选

对来自国内外不同地区的550份水稻资源进行全生育期耐盐性鉴定。设置淡水、0.3%和0.5%盐溶液浇灌3个处理,插秧10d后,通过浇灌不同体积的淡水与海水调至设计浓度对水稻进行不同浓度的盐胁迫处理。分别调查了淡水及0.3%盐处理下水稻株高、有效分蘖数、主穗长度、主穗结实率、单株产量、抽穗期6项农艺性状和0.5%盐处理下的水稻耐盐表型。与淡水浇灌相比,全生育期在0.3%盐溶液处理下,550份水稻(100%)株高显著降低;124份(22.55%)水稻有效分蘖数(90份增加, 34份减少)、414份(75.27%)水稻主穗长度(405份变短、9份增长)、145份(26.36%)水稻主穗结实率(84份减少, 61份增加)、375份(68.18%)水稻单株产量(343份减少, 32份增加)存在(极)显著差异;水稻资源的抽穗期无显著差异。主成分分析表明,主穗结实率、有效分蘖数及单株产量3项性状累计贡献77.25%的变异。根据产量耐盐系数筛选了121份耐盐水稻资源(产量耐盐系数≥0.8),在0.5%盐胁迫持续处理42 d后,筛选了78份耐盐水稻资源(耐盐表型为3级),其中25份水稻资源全生育期在0.3%盐处理下单株产量耐盐系数≥0.8,在0.5%盐胁迫持续处理42 d后的耐盐表型为3级。筛选的耐盐水稻资源为培育耐盐新品种及深入研究耐盐机制提供材料。

Screening and identification of salt-tolerant rice germplasm in whole growth period

Five hundred and fifty rice germplasm collected from different regions at home and abroad were tested at 10 days after transplanting treated with various salt concentrations (0, 0.3%, and 0.5% salinity) during whole growth period, the various salt concentrations were obtained by watering different volumes of water and seawater. Six agronomic-related traits, including plant height, panicle number per plant, main panicle length, seed setting rate, yield per plant and heading date, were investigated under 0, 0.3% salinity treatments, and salt-tolerant phenotype was investigated under 0.5% salinity treatment. Under the salt treatment of 0.3% salinity during whole growth period, the plant height of 550 (100%) rice varieties decreased significantly; and there were significant difference in panicle number per plant of 124 (90 up, 34 down) rice varieties, main panicle length of 414 (405 down, 9 up) rice varieties, seed setting rate of 145 (84 down, 61 up) rice varieties, yield per plant of 375 (343 down, 32 up) rice varieties, while no significant difference in heading date. Principal component analysis showed that 77.25% variation was contributed by the three agronomic-related traits including main spike seed-setting rate, effective tiller number and yield per plant. One hundred and twenty-one salt-tolerant rice varieties with yield salt tolerance index ≥ 0.8 were obtained under 0.3% salinity treatment, 78 salt-tolerant rice varieties with salt tolerance phenotype of level 3 were screened under the durable 42 days salt treatment of 0.5% salinity. There were 25 rice varieties with both the yield salt tolerance index ≥ 0.8 under 0.3% salinity treatment and phenotype of level 3 under the durable 42 days salt treatment of 0.5% salinity. These salt-tolerant varieties can be used for cultivar innovation and the further study on mechanism of salinity tolerance.