Heritability of height, width, resin, rubber, and latex in guayule (Parthenium argentatum)
Heritability of height, width, resin, rubber, and latex in guayule (Parthenium argentatum)
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DOI：
10.1016/s0926-6690(00)00080-7
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发表时间：
2001-05-01
影响因子：
5.9
通讯作者：
Lorenz, G
中科院分区：
文献类型：
--
作者：
Dierig, DA;Ray, DT;Lorenz, G
瓜伊勒是一家生产橡胶和乳胶的工厂，其植物育种并没有像预期或期望的那样有效。据报道，在这种无融合生殖作物中，植株高度、宽度、树脂、橡胶和乳胶含量等性状存在着惊人的大量变异。这项研究旨在计算三个已发布的种质系内部和之间由于环境和遗传影响而产生的总变异性的比例。在1年生、2年生和3年生时测量植株高度；在2年生和3年生时测量植株宽度和乳胶含量；以及在2年生时测量树脂和橡胶含量。每个性状和年份的广义遗传力是通过将基因型除以总方差来估计的。为了估计每个性状的测量方差的遗传成分，从总方差(来自自由授粉(OP)种子繁殖植株的方差)中减去环境效应(来自无性系繁殖植株的方差)。总体而言，无性系繁殖植株的测量性状的平均值的方差低于无融合生殖的OP种子繁殖植株。对每个性状计算的遗传力估计每年都不同。例如，AZ-2系的株高遗传力估计在1岁时为0.84，2岁时为0.47，3岁时为0.0。这些值表明，在该品系中观察到的变异很大程度上归因于生长头两年的遗传效应。当植物经过几个季节的生长时，环境影响会复合，掩盖遗传影响，使有效的选择变得更加困难。同一品系乳胶含量的遗传力第二年为0.97，第三年为0.55。在这项研究中，对所测量的性状的选择似乎在生长的第一年和第二年最有效，在第三年效果逐渐减弱。在本研究之前，大多数选择是在生长3到5年之间进行的，因此表明大多数育种计划缺乏重大进展的原因之一。(C)2001 Elsevier Science B.V.保留所有权利。
Plant breeding in guayule, a rubber and latex producing plant, has not been as effective as predicted or desired. A surprisingly large amount of variability has been reported in this apomictic crop for traits such as plant height, width, resin, rubber, and latex contents. This study was designed to calculate the proportion of the total measured variability due to the environment and the proportion due to genetic influences within and between three-released germplasm lines. Plant heights were measured at 1, 2 and 3-years-of-age; plant width, and latex contents at 2 and 3-years-of-age; and resin and rubber content at 2-years-of-age. Broad-sense-heritabilities were estimated for each trait and year by dividing the genotypic by the total variance. To estimate the genetic component of the measured variance for each trait, the environment effects (variance from clonally propagated plants) were subtracted from the total variance (variance from open-pollinated (OP) seed propagated plants). In general, the variances of the means for the measured traits were lower in the clonally propagated plants compared with the apomictic OP seed propagated plants. The heritability estimates calculated for each trait differed from year to year. For instance, heritability for plant height was estimated in line AZ-2 to be 0.84 at 1 year of age; 0.47 at 2 years of age; and 0.0 at 3 years of age. These values imply that a large portion of the observed variation in this line is attributed to genetic effects in the first 2 years of growth. As the plant grows over several seasons, the environment effects compound, masking the genetic effects, making effective selection choices more difficult. Heritability for latex content for the same line was estimated to be 0.97 for the second year and 0.55 for the third year. Selections for the measured traits in this study appear to be most effective during the first and second years of growth, with effectiveness diminishing during the third year. Most selections previous to this study were performed between 3 and 5 years of growth, thus suggesting one reason for the lack of significant progress in most breeding programs. (C) 2001 Elsevier Science B.V. All rights reserved.