白兰杂种F_1种间杂种优势形成的水分胁迫抗性生理基础

Water Stress Resistance Physiological Foundation for Interspecific Heterosis Formation of Reciprocal F_1 Hybrids of Paulownia fortunei(Seem.) Hemsl.and P.elongata S.Y.Hu

运用林木遗传学和逆境生理学的原理和方法,研究了白兰种间正反杂种F1杂种优势形成的水分胁迫抗性生理基础。结果表明:杂种叶片具有在水分胁迫状态下抗失水、维持叶绿素单位面积质量、保持蛋白质单位面积质量、降低RNase活力升高速率等4种超亲杂种优势现象。蛋白质生物合成抑制剂取得的证据表明水分胁迫状态下双亲叶片RNase活力的升高除涉及到细胞质mRNA翻译外,还可能涉及到叶绿体和/或线粒体RNase的释放、活化、合成,而正反交F1杂种叶片RNase活力升高主要来自于细胞质mRNA的翻译,而与叶绿体、线粒体的关联不密切。

Selecting Paulownia fortunei （Seem.） Hemsl. and P. elongata S. Y. Hu and their interspecific reciprocal F1 hybrids as research materials, and applying the principles and methods of forest-tree genetics and stress physiology, this paper studied the water stress resistance physiological foundation for interspe cific heterosis formation of reciprocal F1 hybrids of P. fortunei （Seem.） Hemsl. and P. elongata S. Y. Hu. The results showed that the leaf blades of reciprocal hybrids had four kinds of the super-parent heter osis, such as resisting water loss, maintaining chlorophyll mass in per unit area, preserving protein mass in per unit area and decreasing RNase activity increase rate under water stress. Evidences from protein bio synthetic inhabitor under water stress indicated that RNase activity increase of parents might be involved in cytoplasmic mRNA translation and RNase release,activation and/or synthesis of chloroplast and/or mitochondria, but RNase activity increase of reciprocal hybrids might originate mainly from cytoplasmic mRNA translation,not very close to chloroplast and/or mitochondria. It is suggested that the above-mentioned no table super-parent heterosis of resistance to water stress the leaf blades of reciprocal hybrids have constitu ted together the stress physiological foundation for heterosis formation of reciprocal F1 hybrids of P. for tunei （Seem.）Hemsl. and P. elongata S. Y. Hu.