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不育系的株行圃和株系圃,主要任务是鉴定和选择。而原种圃和繁殖田则要求在保证纯度的前提下尽量增加繁殖系数,即提高单位面积的繁殖产量。不育系繁殖同制种相比,有有利的一面,也有不利的一面。有利的是不育系繁殖全生育期常比制种田短,季节和茬口的调节较为容易,父母本生育期基本一致,繁殖田花期不遇的风险较小。不利的是父本保持系的分蘖力不如恢复系,早发和足穗较为困难,所以繁殖田的花粉密度常比制种田低。而且根据国内外的研究报导,异品种花粉受精结实往往比同品种花粉有更强的竞争力。目前繁殖田的产量水平常比制种田低,以上两点不利因素可能是重要的原因。
Sterile line of nursery and nursery plant nursery, the main task is to identify and choose. The original nursery and breeding fields are required to ensure the purity of the premise as much as possible to increase the breeding coefficient, that is, to increase the yield per unit area. Male sterile lines have the advantages and disadvantages of breeding. Advantageously, the whole reproductive period of sterile lines is shorter than that of planted ones, and the adjustment of seasons and stubble is easier. The parents are basically the same in their growth period, and the risk of infancy is low. Disadvantage is that the parental maintainer of the tillering power than the restorer line, early onset and foot panicle is more difficult, so the breeding field pollen density is often lower than farming. Moreover, according to the research reports at home and abroad, pollen fertilization and seed-setting of different varieties tend to be more competitive than pollen of the same species. At present, the production level of breeding fields is often lower than that of farming systems. The above two unfavorable factors may be the important reasons.