高分蘖力通常被认为是美国大平原地区冬小麦生产的一个有利特性(Schmidt等,1978).分蘖可使作物在不利的环境条件(如冬季低温或干旱)和比较有利的条件下调节茎数.然而,相当一部份分蘖不能成穗(Bremner, 1969, Austin和Jones, Evans等, 1975).无效分蘖往往高达总蘖数的2/3(Evans和Wardlaw, 1976).不能成穗的分蘖可否认为是光合产物的损耗:多数情况下,禾谷类作物自幼苗发芽后不久就开始形成新的分蘖,直到小花分化(Rawson, 1971; Jewiss, 1972; Evans等, 1975).一旦有效分蘖的穗和茎开始迅速发育,有效蘖即明显占优势,使 High tillering power is generally considered to be a favorable feature of winter wheat production in the Great Plains of the United States (Schmidt et al., 1978). Tillers allow the crop to be adjusted under unfavorable environmental conditions (eg, cold or drought conditions in winter) and more favorable conditions. However, a significant percentage of tillers can not become spikes (Bremner, 1969, Austin and Jones, Evans et al., 1975). Invalid tillers are often up to two-thirds of the total number of tillers (Evans and Wardlaw, 1976). Considered to be a loss of photosynthetic products: In most cases, cereal crops begin to develop new tillers shortly after young seedlings germinate until floret differentiation (Rawson, 1971; Jewiss, 1972; Evans et al., 1975) Stems began to develop rapidly, the effective tiller that is clearly dominant