不同密度下Reid改良系的单株产量杂种优势及配合力

以6个Reid改良自交系为母本,5个Non-Reid、DOM自交系为父本,采用NCⅡ设计,设6.0,7.5,9.0万株/hm~2密度梯度,对单株产量的F_1杂种优势和配合力进行了研究。结果表明:3种密度下,玉米单株产量杂种优势普遍存在,低密度下单株产量杂种优势较高,随密度增加,杂种优势降低,但改良系J1959在高密度下杂种优势却较高。杂交组合×密度的互作极显著存在,组合J2111×5AD宜在6.0万株/hm~2、J1959×5AD宜在9.0万株/hm~2能充分发挥增产作用。配合力方面,6.0万株/hm~2密度下,改良系J2111一般配合力效应最高,为7.09;7.5万株/hm~2和9.0万株/hm~2密度下,改良系J1959一般配合力效应均最高,分别为7.18和13.48,说明改良系J1959更适于密植环境;组合J1959×5AD的特殊配合力效应随密度增高而增高,分别为-2.14,3.13,9.32,组合J2111×S122的特殊配合力效应随密度增高而降低,分别为6.04,-2.19,-9.47,表明前者适于高密度环境,后者适于低密度环境。

Heterosis and Combining Ability of Yield per Plant in Reid Improved Lines of Maize under Different Densities

Using six improved lines of Reid as female parents and five inbred lines of Non-Reid and DOM as male parents,adopting NC II design,setting 60 000,75 000 and 90 000 plant/hm2 density gradient,we studied heterosis and combining ability of yield per plant of F1.The results showed that heterosis of yield per plant was ubiquitous under three densities,under low density,heterosis of yield per plant was higher,and with the increase of density,heterosis decreased,but the improved line J1959 had high heterosis under high density.The interaction of hybrid combination×density existed extremely significantly,the combination of J2111 × 5AD could give full play to increase production under 60 000 plants/hm2 density,while the combination of J1959×5AD was under 90 000 plants/ hm2 density.As for combining ability,under 60 000 plants/hm2 density,the improved line J2111 had the highest GCA effect (7.09);Under 75 000 plants/hm2 and 90 000 plant/hm2 density,the improved line J1959 had the highest GCA effect (7.18 and 13.48,respectively),which illustrated that the improved line J1959 was more suitable for close planting;The SCA effect of combination J1959×5AD increased with the increase of density (-2.14,3.13 and 9.32,respectively),and the SCA effect of combination J2111 × S122 decreased with the increase of density (6.04,-2.19,-9.47,respectively),which indicated that the former was suitable for high density environment,while the latter was suitable for low density environment.