籽粒黄熟度对杂交水稻种子活力的影响

为明确籽粒黄熟度对杂交水稻种子活力的影响,探究杂交水稻高活力种子适宜收获期的感官指标,于2016-2017年以深两优1813、隆两优1813、Y两优1128、创两优华占和Ⅱ优838为材料进行杂交水稻制种,通过不同收获时期形成籽粒黄熟度不同的群体,系统分析了不同籽粒黄熟度群体间种子活力、水分、千粒重及内含物的差异。结果表明,在不同品种间,籽粒黄熟度的增加速率存在明显差异。随着籽粒黄熟度的增加,种子活力先增加后趋于稳定;种子水分先降低后趋于稳定;种子千粒重逐渐增加,但差异不显著;种子的直链淀粉、总淀粉、蛋白质及可溶性糖含量均先增加后趋于稳定。当籽粒的黄熟度为75%~90%时,种子发芽率、发芽势、发芽指数和活力指数均处于高值水平,且差异不显著;种子水分和千粒重均未达到显著差异。相关性分析表明,籽粒黄熟度与种子发芽率、活力指数呈极显著正相关,相关系数分别为0.870 3^**和0.664 0^**;与种子水分呈极显著负相关(R²=-0.842 4^**),与种子千粒重相关性不显著(R²=0.197 2)。籽粒黄熟度与种子内含物均无显著相关性,但种子发芽势、发芽指数和活力指数均与种子内含物达到显著相关。综上,籽粒黄熟度为75%~90%可以作为杂交水稻高活力种子生产适宜收获期的感官指标。本研究结果为杂交水稻高活力种子生产提供了理论参考。

Effects of Yellow-seed Percentage on Seed Vigor in Hybrid Rice Seed Production

The objective of this study was to seek effect of yellow-seed percentage on seed vigor, and determine the optimum harvesting time of hybrid rice seed based on sensory index. Field experiments were conducted with varieties Shenliangyou1813, Longliangyou1813, Yliangyou1128, Chuangliangyouhuazhan, Ⅱyou838, and seed vigor, moisture content, 1000-grain weight and storage substance content were measured among different yellow-seed percentage populations constructed by different harvesting time. The results revealed that a significant difference was observed in the increasing rate of yellow-seed percentage among different varieties. With the increasing of yellow-seed percentage, seed vigor increased firstly and then kept stable while seed moisture decreased firstly and then kept stable. Additionally, 1000-grain weight increased gradually, but an insignificant difference was observed. Moreover, seed amylose content, total starch content, protein content and soluble sugar content increased firstly and then kept stable. When the yellow-seed percentage ranged from 75% to 90%, germination percentage, germination energy, germination index and vigor index kept at high level, and an insignificant difference was obtained in both seed moisture and 1000-grain weight. Moreover, a significantly positive correlation was observed between yellow-seed percentage and germination percentage and vigor index (R²=0.870 3^** and R²=0.664 0^**, respectively). A significantly negative correlation was obtained between yellow-seed percentage and seed moisture (R²=0.842 4^**), and there was no obvious correlation between yellow-seed percentage and 1000-grain weight (R²=0.197 2). There was no correlation between yellow-seed percentage and storage substance content, but a significant correlation was obtained between seed vigor and storage substance content. Therefore, yellow-seed percentage (75%~90%) could be recommended as sensory index predicting the optimum harvesting time during hybrid rice seed production with high vigor. Moreover, these results in this study provided references for hybrid rice seed production with high vigor.