通过选择耐锈性小麦品种,很难改善雨养条件下小麦生产水平和植株结构。高秆型小麦相应的也有较长的根系;所以,人们倾向于选择高秆类型品种。除了直接选择根的长度之外,在雨养条件下粘重黑棉土地上,还难以找到一个合适的类型。然而,近期对印度北部轻质冲积土上有关根系的重要研究表明,不同水分含量的土壤条件下种子根和节根的不同作用(Sirhi等,1978;Vprety等,1980)。本研究的目的旨在评价节根在雨养条件下的生物活性及它们的作用。把在雨养条件下播种的不同小麦品种的幼苗移栽到盛有常规土壤的盆钵中,再分别把盆钵置于温室和田间。移栽前,除去幼苗上的种子根。1986—1987年间,每年将试验稍加改进各重复一次。 1986—1987年,把“Sujata”(雨养区),“DSN”(国际 It is difficult to improve the wheat production level and plant structure under rain-fed conditions by selecting wheat varieties that are resistant to rust. Tall stalks also have longer roots accordingly; therefore, people tend to choose tall stalks. In addition to the direct selection of the length of the root, it is difficult to find a suitable type on a sticky black cotton soil under rainfed conditions. However, recent important studies on root systems in light alluvial soil in northern India show different roles of seed and root under soil conditions with different moisture contents (Sirhi et al., 1978; Vprety et al., 1980). The purpose of this study was to evaluate the biological activity of root-nodules under rainfed conditions and their role. Seedlings of different wheat cultivars planted under rainfed conditions were transplanted to pots containing conventional soil and the pots were placed in greenhouses and fields, respectively. Before transplanting, the seedlings on the seedlings are removed. During 1986-1987, experiments were repeated a little each year. From 1986 to 1987, the “Sujata” (rain-fed area), “DSN” (International