Genetic diversity of photosynthetic characters in native populations of Triticum dicoccoides
Genetic diversity of photosynthetic characters in native populations of Triticum dicoccoides
复制标题
二粒小麦本地群体光合性状的遗传多样性
作者：
B. Carver;E. Nevo
野生二粒小麦（Triticum dicoccoides Korn）在抗病性和具有重要经济意义的形态生理性状方面表现出广泛的遗传多样性。我们的目标是测试遗传变异（VG）的光合特性内和本地人口之间的采样从以色列的三个生态地理区域，并确定潜在的来源，高光合效率为未来的小麦改良。在一个相对狭窄的地理范围内的野生二粒小麦分布中心（约旦河谷上游）的样本加入表现出最大的多样性，每单位叶面积（A）或每单位叶绿素（A/Chl）的CO2同化率。遗传变异是不存在的内部CO2浓度（Ci）和水分利用效率（WUE）和气孔导度（GS）普遍缺乏。叶面积，虽然相当可变，是不是一个重要的辅助因子在评估光合作用的遗传潜力。在一个给定的人口内的加入显示10倍以上的变化，在A和A/Chl比从不同地点在一个地区抽样的人口。最高的光合效率来自高地草原人口位于边缘的栖息地向南延伸到以色列。一些具有高光合能力（A=32 μ molm-2s-1）而叶片大小不显著缩小的材料是一种潜在的有价值的遗传资源，但尚未开发用于六倍体（T.小麦）小麦
Wild emmer wheat (Triticum dicoccoides Korn) has shown wide genetic diversity for disease resistance and morpho-physiological traits of economic importance. Our objectives were to test for genetic variation (VG) in photosynthetic characteristics residing within and between native populations sampled from three ecogeographical regions of Israel, and to identify potential sources of high photosynthetic efficiency for future wheat improvement. Accessions sampled in the center of wild emmer distribution (upper Jordan Valley) in a relatively narrow geographical range showed the greatest diversity in CO2-assimilation rate per unit leaf area (A) or per unit chlorophyll (A/Chl). Genetic variation was absent for internal CO2 concentration (Ci) and water-use efficiency (WUE) and generally lacking for stomatal conductance (gs). Leaf area, although quite variable, was not a significant cofactor in assessing genetic potential for photosynthesis. Accessions within a given population showed 10-times more variation in A and A/Chl than populations sampled from different locations in a region. Accessions with the highest photosynthetic efficiency were derived from upland steppic populations located in marginal habitats extending southward into Israel. Some accessions having high photosynthetic capacity (A=32 μmol m-2 s-1) with no significant reduction in leaf size constitute a potentially valuable genetic resource yet untapped for genetic improvement of hexaploid (T. aestivum L.) wheat.