小麦茎秆强度的鉴定方法研究

Determination of Resistance to Lodging by Stem Strength in Wheat

茎秆强度决定小麦品种的抗倒伏性能,但现有鉴定茎秆强度的方法还不完善。用秆强测定器测定了661个小麦品种和1183个F2代单株,结果表明,乳熟至蜡熟期是鉴定茎秆强度的适宜时期,利用秆强测定器可从F2代分离群体中鉴定出强秆单株。成熟时茎秆强度降低,不易区分茎秆强度的品种间差异。通过分析30个品种的茎秆强度值与茎秆解剖性状的相关性,发现上部节间的髓腔大小与茎秆强度呈极显著负相关,而下部节间的茎秆粗度与茎秆强度呈极显著正相关。由于穗部重量和生物产量与茎秆强度呈极显著正相关,育种家应选择秆强与穗重相适应的品种以提高产量潜力和稳产性。

Stem strength affects directly the resistance of wheat variety to lodging. Unfortunately the determination of the stem strength is now not perfect in wheat breeding and genetics. In this study a prostrate tester was used for testing the stem strength of 661 wheat varieties and 1183 plants of a F2 population. The results showed that the suitable time to determine the stem strength should be from milk stage to dough ripe stage. The stem strength at the maturity would decrease and it was not easy to discover the difference among the varieties. The single plant with strong stem could be determined from a F2 population by the prostrate tester. By testing the relation between the stem strength and anatomic characters of 30 varieties, a significant negative relation between the pith diameter of the upper internodes and the stem strength was discovered. On the other hand,there was a significant positive relation between stem diameter of the lower internodes and stem strength. It was suggested that wheat breeder should breed the cultivar with a strong stem, which may suit to the spike weight because the spike weight and biomass yield were significantly related to the stem strength.