籼粳细胞质和海拔差异对水稻F_1配子体基因型的选择效应

Selective effect of Indica-japonica cytoplasm and altitude variation on the gametic genotype of F_1 in rice

为研究籼粳细胞质背景和海拔引起的环境温度变化对水稻F1配子体基因型的选择效应,利用云南海拔2 650 m高寒稻区种植的地方粳稻老品种小麻谷与具有籼稻细胞质背景的改良品系南34为亲本,分析比较了在400、1 860、2 200 m 3个不同海拔下正反交F1的花粉育性和小穗育性,以及在3个不同海拔下产生的F2群体的生物学性状。结果表明:在3个不同海拔、粳稻细胞质背景下的杂种F1的花粉育性和小穗育性均显著高于其在籼稻细胞质背景下的表现,其中花粉育性的差异更为明显。除细胞质外,海拔也同样极显著影响杂种F1的花粉育性,但对其小穗育性影响很小。在不同海拔下产生的F2群体的生物学性状存在显著或极显著差异,同一海拔下产生的正反交F2群体间的生物学性状也存在显著差异。结果表明不同细胞质背景和海拔差异对水稻F1的雄配子基因型具有明显的选择效应,选择压力引起雄配子的败育导致其后代孢子体的基因型发生选择。

In order to make clear the selective effects of the environmental temperature induced by altitude on the FI gametic genotype selection and on the genetic variation in their progenies under indica-japonica cytoplasmic backgrounds in rice. The pollen fertility and spikelet fertility were analyzed in reciprocal FI populations planted at three different altitudes of 400 m, 1 860 m and 2 200 m; and the biological characteristics in F2 populations generated from reciprocal hybrids at three altitudes were analyzed. The material parents were XMG, japonica rice landrace grown at Yunnan alpine region at 2 650 m, and N34, an improved line that cytoplasm donated by indica rice. The results showed that the Fls under japonica cytoplasmic backgrounds had the fertility significantly higher than the Frs under indica cytoplasmic backgrounds at all altitudes. Especially, pollen fertility was much different between the reciprocal hybrids. Beside cytoplasm, altitude had significant effects on pollen fertility of the F~ hybrids, but the effect was not obvious on spikelet fertility. The biological characteristics of F2 populations generated from hybrids at the different altitudes had significant or extremely significant differences, and the biological characteristics of F2 populations generated from reciprocal hybrids at same altitude also had significant differences. It indicated that the cytoplasmic backgrounds and altitude variation had selecting pressure on male gametic genotype of Fls, and such fertility difference could result in genotype selection on descendant progenies.