低磷胁迫下玉米自交系配合力分析

缺磷是限制作物生产的重要因素之一。通过遗传改良提高玉米杂交种的磷吸收利用能力,是提高磷肥利用率的一条重要途径。本研究利用磷肥长期定位田,在前期磷高效自交系筛选的基础上,对低磷胁迫下玉米自交系的配合力进行分析,以期为磷高效育种选择亲本提供依据。研究结果表明,鲁原92×7922为高磷高效型杂交组合,减产率达67.2%;Mo17×7922为低磷高效型杂交组合,减产率只有3.5%。耐低磷育种中,高配合力自交系为CA200和Mo17;低配合力自交系为丹黄02、107、原引1号、鲁原92、3189、Oh43和黄C;中配合力自交系为91041-1、CA170、L种和7922。低磷条件下,组合产量与空秆率、成熟期熟相呈负相关,即早熟型且空秆少的玉米品种较为耐低磷胁迫。

Evaluation of the Combining Ability of Maize Inbred Lines Under Low Phosphorus Stress

Low phosphorus(P) stress is one of the major limiting factors in crop productivity. Breeding for P-efficient cultivars is a promising way to increase P fertilizer use efficiency. Based on the preliminary work on selection P-efficient inbreds on a long-term P fertilizer experimental field, the combining ability of selected inbreds was evaluated under low P stress. It was shown that the yield of hybrid 92×7922 was only high at high P, while at low P, it reduced by 67.2%. On the contrary, hybrid Mo17×7922 was tolerant to low P with low yield reduction rate(3.5%) at low P. For breeding low P- tolerant hybrids, inbred CA200 and Mo17 had higher combining ability, while the combining ability of inbreds Danhuang02, 107, Yuanyin 1, Luyuan 92, 3189, Oh43, Yellow C was low. That of 91041-1, CA170, L-race, 7922 was in the intermediate. At low P, the yield of maize hybrids had a negative close relationship with barren-cob ratio(percentage of plants with infertile cob in total plants per hectare) and duration of growth period, that is, early-mature cultivars with low barren-cob ratio tend to be more tolerant to low P stress.