The Green Revolution of the 1960s introduced semi-dwarf cultivars of rice that had reduced lodging and increased harvest indexes. The mutant allele of Semi Dwarf 1 (SD1) is the gene underlying the Green Revolution advances in rice yield. Since that time, most of the commercial semi-dwarf cultivars carry a mutation in SD1. Unlike japonica rice cultivars containing weak functional SD1 alleles, indica rice cultivars owed their diminished stature to a null mutation in SD1. It has been proposed recently that increasing plant height and subsequently plant biomass will increase grain production in semi-dwarf cultivars used in super rice breeding programs. In this study, we evaluated the potential benefit of the weak functional allele of SD1 from japonica rice on yield improvement in the indica rice background. We found that the Green Revolution gene SD1 has pleiotropic effects on tiller number and spikelets per panicle, in addition to plant height in rice. The introduction of the weak allele SD1-EQ from the japonica cultivar ‘Nipponbare (Np)’ led not only to a substantial increase in plant height but also to an increase in yield per plant in the indica cultivar ‘9311’. This result was further confirmed in CRISPR/Cas9-mediated knockout mutants. In addition, heterosis for yield-related traits was detected at the SD1 locus, and SD1-EQ exhibited a potential improved yield in hybrid rice lines. This study provides evidence that the weak functional SD1 allele from japonica rice cultivar ‘Np’, SD1-EQ, is an excellent genetic resource for the improvement of indica rice lines with null alleles of SD1, in the post-Green Revolution era.

1960年代的绿色革命引入了半矮化水稻品种，减少了倒伏并提高了收获指数。Semi Dwarf 1（SD1）的突变等位基因是水稻革命中绿色革命进步的基础基因。从那时起，大多数商业半矮化品种在SD1中携带一个突变。与粳米含有弱功能水稻品种SD1等位基因，籼水稻品种欠他们的身形减少在无效突变SD1。最近已经提出，增加植物高度并随后增加植物生物量将增加超级稻育种计划中使用的半矮栽培品种的谷物产量。在这项研究中，我们评估的弱功能性等位基因的潜在益处SD1从粳稻在产量提高水稻籼大米背景。我们发现，绿色革命基因SD1除水稻株高外，还对分till数和每穗小穗有多效性。引入弱等位基因的SD1-EQ从粳稻品种不仅导致在植物高度大幅度增加，而且在每株植物的增加的产量“日本晴（NP）”d品种'9311'。CRISPR / Cas9介导的敲除突变体进一步证实了这一结果。另外，在SD1位点检测到与产量相关性状的杂种优势，并且SD1-EQ在杂交水稻品系中表现出潜在的产量提高。这项研究提供的证据表明，弱功能SD1从等位基因粳水稻品种中NP'，SD1 - EQ，是改善一个很好的遗传资源籼水稻品系与无效等位基因SD1，在后绿色革命时代。