摘要
选择低温弱光抗性水平不同的欧洲温室型、欧亚杂交型、华北温室型、华北露地型黄瓜(Cucumis sati- vus L.)的16个品种为试验材料,以光合代谢为切入点,开展苗期光合速率、光补偿点、1,5-二磷酸核酮糖羧化酶 (rubisco)活性和叶绿素a荧光动力学曲线的系统研究,结果表明:单一偏低温和偏低温弱光协效应未明显伤害光合系统,而临界低温可能伤及PSⅡ;偏低温和弱光组合时,弱光对黄瓜幼苗的影响起主导作用,弱光与临界低温组合时,临界低温起主导作用;偏低温弱光(单一弱光)下的叶面积增长量和临界低温下的冷害指数可分别作为评价黄瓜对偏低温弱光(单一弱光)耐受性和临界低温耐受性的比较稳定可靠的指标,据此设计了相关的评价指标体系。用117个重组自交系为材料,以弱光下叶面积增长量为指标进行弱光耐受性评价并以RAPD、AFLP、SSR分子图谱为基础,通过区间作图,检测到5个与黄瓜弱光耐受性有关的QTLs。采用mRNA差异显示银染技术克隆得到黄瓜冷敏型品种津研4号低温锻炼中特异表达基因的cDNA克隆(ccr18),其大小为639 bp。在基因组中以单拷贝或低拷贝形式存在。序列同源性比较表明它与拟南芥[Arabidopsis thaliana(L．)Heynh．]染色体ⅣBAC库中的 F14P3基因组序列具有88％的同源性。
Sixteen Cucumber （Cucumis stativus L. ） with different adaptability to lower temperature and poor light, including European greenhouse type, European cross Asian greenhouse type, Northern China open-field type were employed in this paper. Indexes on photosynthetic metabolism and morphology under the stress of low temperature and poor light were measured. The results were：l ） The PSII system didnt be harmed under the stress of poor light and lower temperature or lower temperature accompanied with poor light, while the critical low temperature provided a much stronger stress force to the cucumber seedling and may lead to injury to PSⅡ. 2） The poor light was the dominant stress factor when accompanied With lower temperature; however, the critical low temperature was the dominant stress factor when accompanied with poor light. 3） Chilling injury index under critical low temperature and the increase of leaf area under poor light may act as reliable evaluation index for critical low temperature and poor light tolerance in cucumber respectively, and furthermore, the evaluation system of tolerance to poor light and critical low temperature was designed based on the indexes above.
Tolerance of poor light was evaluated in 117 recombination inbred lines by using the evaluation system established in this paper. For QTL detection, the interval mapping method was employed based on a molecular genetic map constructed with RAPD, AFLP and SSR markers. Five putative QTL were mapped in three linkage groups.
A strategy of mRNA differential display was used for screening specific expression genes for cold acclimation in cucumber. Jingyan No. 4, a cold sensitive cuhivar of cucumber, was treated under the conditions of 8 ℃ for 0, 6, 12, 24, 48 and 72 h, respectively, at the two true leaves stage. A cold specific cDNA clone named as ccrl8 was obtained. Sequencing data showed the size of the cDNA clone was 639 bp in length. It shared 88 % sequence with a BAC F14P3 genomic sequence of Arabidopsisthaliana chromosome at protein sequence level.
出处
《中国蔬菜》
北大核心
2005年第B10期7-12,共6页
China Vegetables
基金
北京市自然科学基金重点项目(6971002)
关键词
黄瓜
低温
弱光
耐受性
机理
Cucumber, Low temperature, Poor light, Tolerance ability, Mechanism, Application
作者简介
王永健，男，研究员，北京市农林科学院蔬菜研究中心，100089，电话：010—51503166，E—mail：wangyongjian@nercv．com
