水稻小粒不育系新组合卓两优141混播制种优势分析

Abstract

<p id="C3">Traditional hybrid breeding is backward, low benefit, and high cost, which restricts the promotion and application in hybrid rice. However, Small Grain TMS lines are easy to be mechanically separated after mixed-sowing and mixed-harvesting. Their application will promote the realization of complete Mechanization of Hybrid Rice Seed Production, leading to the reduction of cost and the improvement of seed production efficiency. In this study, we investigated the agronomic characteristics and outcrossing rates suitable for Mechanization of Hybrid Rice Seed Production, using the Small Grain male sterile line Zhuo 201S, Large Grain restorer line R141, and their combination Zhuoliangyou 141 as materials for mixed-sowing and large-scale seed production practice. The results demonstrated that compared with the control TMS C815S, Zhuo 201S plants were shorter, exhibiting longer and more erect ear, fewer glume opening, lower percentage of panicle enclosure and germination on ears. Moreover, Zhuo 201S plants were resistant to smut disease but sensitive to “920” treatment and had weak seed-shattering characteristic. However, R141 plants were tall and insensitive to environmental temperature with large amount of pollen and a long florescence. Both Zhuo 201S and R141 had good outcrossing characteristics. The grain thickness of Zhuo 201S and R141 was 1.71 mm and 2.23 mm, respectively. The 1000-grain weight of Zhuo 201S and R141 was 14.00 g and 28.20 g, respectively. Due to the significant difference in grain sizes, the hybrid F₁ seeds could be easily separated with the male parent seeds through a special sieve with narrow and long apertures. The percentage of male parent seeds mixed in hybrid seeds was 0 while the hybrid seed loss rate was 2.31%, suggesting that the seed purity met the standards for Mechanization of Hybrid Rice Seed Production. Compared with the traditional seed production mode, the basic seedling of male parent was reduced by 85%, the capacity of female parent was increased by 20%, the seed production yield was increased by 21.37%, and the comprehensive benefit of seed production was increased by 31.4%. Zhuoliangyou 141 was endowed with the advantages suitable for mechanized production by mix-sowing, with excellently agronomic traits and outcrossing properties along with huge difference in grain size from its parents. Therefore, the whole process of Zhuoliangyou 141 mechanized seed production had a broad application prospect.