川西CHA杂交小麦产量优势构成分析

Studies on Heterosis Components of Yield of CHA Hybrid Wheat in West Sichuan

利用99个不完全双列杂交组合和17个CHA杂种．研究了在单株点播和正常密植条件下川西CHA杂交小麦的产量及产量构成超标优势特点。结果表明：1、在单株条件下，产量超标优势较大（＞15％）的组合是稳、粒、重三要素在较高水平上的协调提高的结果，产量优势主要来源于穗粒数优势和一定的有效稳优势。2、在密植条件下．具有较大产量超标优势（＞10％）的组合产量优势主要来源于穗粒数和千粒重优势。并以稳粒数优势起主导作用。3、单株；点播条件下的产量优势大于密植。单株点播下的产量超标优势不能预测正常密植下杂交组合的产量超标优势．而只能作为参考，要正确评价和预测杂交小麦的产量优势，只有在密植条件下进行。4、产量优势较大的组合都是稳、粒、重三要素在较高水平协调统一的结果。千粒重是限制川西CHA杂交小麦产量提高的主要因素．在CHA杂交小麦高产的育种和栽培中，应在维持产量三要素在较高水平协调统一的基础，将重点放在粒重的提高上。5、杂交小麦产量优势近似地等于有效稳、穗粒数和千粒重优势之代数和。

99 crosses from 11× 9 incomplete biserial cross and 17 CHA hybrid wheat were used to investigate thc heterosis over check ofyield and its components of CHA hybrid wheat in west Sichuan. The results indicated that: 1. The crosses with larger yield heterosis over check(> 15 % ) under dibbled planting wcre that the three yield components were larger and harmonious. and the yield heterosis stemed from the heterosis of spikes per plant and the larger heterosis per spike. 2. 1000-grain weight was the main factorsof three yield components to restrict the grain yield under thiek planting. The yield heterosis over check (>10% ) mainly stemmedfrom the heterosis of grains per spike 1000-grain weight. and grains jper spike played the important roles. 3. The heterosis overcheck of yield in dibbled planting was higher than that in thick planting. The yield heterosis over check in dibbled planting didn'tforcast the one in thick planting, only the heterosis over check of yield in thick planting can be used to correctly appraise and forcastthat of CHA hyorid wheat. 4, The ciosses with larger heterosis over check of yield in the two planting densities were due to theharmoniousness of three yield components in higher level. 1000-grain weight was themajor factors to restrict raising the grain yieldof CHA hybrid wheat in west Sichuan. Raising 1000-grain weight of CHA wheat should be put into the focal point of the breedingand cultivation for CHA hybrid wheat with high yield in Sichuan. 5. The heterosis of yield was approximately equal to the algebraic sum of the heterosis from the three yield components.