近年来在水稻杂交后代的选择上,愈来愈多地采用集团选种法,其特点是在低世代中仅按育种要求的性状进行混合选择,混收大量单株的种子(对每个单株来说,则是只收极少量的种子),将单株选择推迟到第5—6代方始进行,尽可能保持低世代的丰富的变异个体,以避免因选择效率不高,使许多优良单株落选。在采用集团选种法时,如仍沿用一般的栽培密度(5×4寸),则占 In recent years, the choice of hybrid rice progeny, more and more use of group selection method, which is characterized by low-generation only in accordance with the requirements of the breeding mix selection, mixing a large number of individual seeds (for each single Strain, it is received only a very small amount of seeds), the plant will be delayed until the first 5-6 to choose the beginning, as far as possible to maintain low-generation rich variant individuals, to avoid the inefficiency due to the selection, so many good Single plant failure. In the use of group selection method, if still use the general planting density (5 × 4 inch), then accounted for