棕榈半同胞子代家系苗期测定及优良家系选择

【目的】探究棕榈苗期生长遗传变异规律,筛选出苗期速生且遗传品质优良的棕榈家系,为棕榈的遗传改良提供参考。【方法】以72个棕榈半同胞家系的1.5年生幼苗为材料,观测其苗高、地径、干质量、鲜质量、条形叶和掌状叶数6个生长性状,进行遗传分析;以聚类分析法与性状表现水平分析法相结合筛选优良家系,并配合单株选择,筛选优良单株。【结果】棕榈苗期生长性状表型变异丰富且在各家系间差异极显著(P<0.001),家系遗传力变化范围为0.842~0.961,均表现为较高强度遗传;从中选出7个优良家系,中选家系的地径、干质量、掌状叶数的现实增益分别增加了18.03%、33.50%、26.77%,其遗传增益分别为16.28%、29.38%、22.51%。从7个优良家系中筛选出32株优良单株,其地径、干质量、掌状叶数的遗传增益分别增加了42.72%、97.86%、59.82%,其现实增益分别增加了60.77%、139.20%、85.09%,选择效果显著。【结论】棕榈幼苗在家系间具有很大的选育潜力,开展其早期选择研究,能为棕榈良种选育提供参考,选择出的优良家系及优良单株可为棕榈遗传改良及后续研究工作提供极佳的种质材料。

A half-sib progeny test and juvenile selection of Trachycarpus fortunei

【Objective】The juvenile selection and breeding of forest palm are beneficial to shorten the breeding cycle and speed up the breeding process. Palm(Trachycarpus fortunei) is a widely cultivated economic species in the south of China, that plays an important role in garden and fiber industry. In order to explore the growth regularity of palm seeding and select the fast-growing families with a good genetic quality, this study is focused on the growth variability of seeding traits of palm among different half-sib families. The purpose was to provide a valuable reference for genetic improvement of palm.【Method】In this study,the 1.5-year-old seedlings of 72 half-sib families of palm were used as the research materials. Using a completely randomized block design, the six growth traits of seedling height, diameter, dry weight, fresh weight, number of the stripe leaf and palmate leaf of palm were investigated. Then, the SPSS 21.0 software was used for an analysis of variance, and the HalfsibSS 1.0 software was used to estimate genetic parameters and the genetic correlation analysis. The elite families were selected by the cluster analysis and level of the trait showing analysis. And the individual selection was carried out to select excellent individuals.【Result】The growth trait statistics and analysis of variance at the seedling stage showed that the phenotypic variation of growth traits among different families was abundant and extremely significant (P<0.001), which provided the basis for breeding excellent families. The results of the estimation of genetic parameters indicated that the family heritability of the six growth traits ranged from 0.842 to 0.961, and the individual heritability ranged from 0.490 to 1.850, all of which showed a strong inheritance. They were specifically manifested as height>striped leaf amount >diameter>dry weight>fresh weight>palm leaves amount. The results of the genetic correlation analysis between the six traits showed that the stripe leaves amount was negatively related to the other traits, and the other traits were positively related. Based on the selection of diameter, dry weight and palm leaves amount, seven elite families were selected. Compared with the selected population, the realistic gain of diameter, dry weight and number of palmate leaves amount of the selected families increased 18.03%, 33.50% and 26.77%, respectively. Its genetic gain was 16.28%, 29.38% and 22.51%, respectively. Based on the selection of seedling height, 32 elite individuals were selected from seven excellent families. The genetic gain of diameter, dry weight and palmate leaf amount increased to 42.72%, 97.86% and 59.82%, respectively. The realistic gain was 60.77%, 139.20% and 85.09%, respectively.【Conclusion】The seedling of palm has a great potential for breeding .Its early selection can effectively improve the genetic quality and shorten the breeding cycle. The selected families and elite individuals can provide excellent breeding materials and aid subsequent research on palm.