ABSTRACT

Conventional production of hybrid rice seeds is based on sowing and transplanting parental lines separately (‘separate seeding and transplanting’, SST). To decrease the labour inputs of field management, a labour-saving model was implemented under a strategy of directly seeding the two parents as a mixture (‘mixed direct seeding’, MDS) to produce hybrid seeds. The strategy utilized a ‘yellow-hull/red-hull’ pair, ensuring that the female parent could be easily separated from the male parent after mixed harvesting. To assess the effects of MDS on seed production, two pairs, P88S/G-4 and Y58S/G-15, were tested and compared with those under SST at the same female/male seed ratio of 5:1 in 2015 and 2016. The parental lines for two pairs flowered synchronously, and the male sterile lines presented a high total stigma exertion rate in SST that ranged from 75.82% to 93.27%. At maturity, the hybrid seeds generated on seed parents were harvested together with those from pollen parents, and later, the hybrids were successfully colour sorted at a correctness rate of more than 99.90% on a machine. In MDS, the heading date of tested lines was advanced by 2~6 days. The outcrossing rate was improved by 8.59% and 7.61%, and the total panicle number increased by 4.78% and 5.80%, respectively. Ultimately, the actual yield in MDS significantly exceeded that in SST by 12.56% for P88S/G-4 and 8.95% for Y58S/G-15. This model succeeded in recycling hybrid seeds via color sorting and seems promising for decreasing labour inputs in hybrid seed production.

摘要

杂交水稻种子的常规生产是基于单独播种和移植亲本（“单独播种和移植”，SST）。为了减少田间管理的劳动力投入，在将两个亲本作为混合物直接播种（“混合直接播种”，MDS）以生产杂交种子的策略下，实施了节省劳力的模型。该策略使用了“黄色-船体/红色-船体”对，以确保混合收获后母本可以很容易地与母本分开。为了评估MDS对种子生产的影响，在2015年和2016年，以相同的雌/雄种子比例为5：1对两对P88S / G-4和Y58S / G-15进行了测试，并与SST下的对进行了比较。两对的育苗线同步开花，雄性不育系在SST中具有较高的总柱头使用率，介于75.82％至93.27％之间。成熟时，将在亲本上产生的杂种种子与花粉亲本一起收获，然后在机器上以99.90％以上的正确率成功地对杂种进行了颜色分选。在MDS中，测试行的行进日期提前了2〜6天。杂交率提高了8.59％和7.61％，总穗数分别提高了4.78％和5.80％。最终，P88S / G-4的MDS实际产量大大超过SST的实际产量，而Y58S / G-15的实际产量则达到8.95％。该模型通过颜色分类成功地回收了杂交种子，并且似乎有望减少杂交种子生产中的劳动力投入。将种子亲本中产生的杂种种子与花粉亲本中的种子一起收获，随后，在机器上以99.90％以上的正确率成功地对杂种进行了颜色分选。在MDS中，测试行的行进日期提前了2〜6天。杂交率提高了8.59％和7.61％，总穗数分别提高了4.78％和5.80％。最终，P88S / G-4的MDS实际产量大大超过SST的实际产量，而Y58S / G-15的实际产量则达到8.95％。该模型通过颜色分类成功地回收了杂交种子，并且似乎有望减少杂交种子生产中的劳动力投入。将种子亲本中产生的杂种种子与花粉亲本中的种子一起收获，随后，在机器上以99.90％以上的正确率成功地对杂种进行了颜色分选。在MDS中，测试行的行进日期提前了2〜6天。杂交率提高了8.59％和7.61％，总穗数分别提高了4.78％和5.80％。最终，P88S / G-4的MDS实际产量大大超过SST的实际产量，而Y58S / G-15的实际产量则达到8.95％。该模型通过颜色分类成功地回收了杂交种子，并且似乎有望减少杂交种子生产中的劳动力投入。测试行的行进日期提前了2〜6天。杂交率提高了8.59％和7.61％，总穗数分别提高了4.78％和5.80％。最终，P88S / G-4的MDS实际产量大大超过SST的实际产量，而Y58S / G-15的实际产量则达到8.95％。该模型通过颜色分类成功地回收了杂交种子，并且似乎有望减少杂交种子生产中的劳动力投入。测试行的行进日期提前了2〜6天。杂交率提高了8.59％和7.61％，总穗数分别提高了4.78％和5.80％。最终，P88S / G-4的MDS实际产量大大超过SST的实际产量，而Y58S / G-15的实际产量则达到8.95％。该模型通过颜色分类成功地回收了杂交种子，并且似乎有望减少杂交种子生产中的劳动力投入。