摘 要

本研究开展了96个苦楝家系的果实、种核性状的变异规律研究，分析了家系间和家系内的性状变异。主要结论如下：

（1）家系间的千粒重、果实大小及种核大小均存在极显著差异，其中千粒重高于均值的家系有24个，占25.00%，果长高于均值的家系有41个，占42.71%，果宽高于均值的家系有29个，占30.21%，核长高于均值的家系有43个，占44.79%，核宽高于均值的家系有31个，占32.29%。

（2）家系间的变异系数由高到低依次千粒重、果宽、核宽、果长、核长、核形系数、果形系数；家系内变异系数由高到低依次核长、核宽、核形系数、果长、果宽、果形系数。家系内低于果长变异系数均值的家系有52个，低于果宽变异系数的家系有52个；低于核长变异系数的家系有59个，低于核宽变异系数的家系有57个。

（3）基于千粒重、果实/种核形状指标的聚类分析，将96个家系分为5类，第一类群的家系表现为千粒重、果实大小、种核大小中等；第二类群的家系千粒重大，果实、种核大，果实圆形、种核近圆形；第三类群，千粒重，果实、种核大小与很小，而果形系数和核形系数最大，表现为最为细长；第四类群的家系千粒重略高于第三类和第五类，而果长低于第三类和第五类，果宽则相反，果形和核形系数与第一类相当；第五类群千粒重小，果长小，种子细长型。

（4）基于果实/种核形状指标变异系数的聚类分析，将96个家系分为7类，果实大小及形状变异系数从低到高依次为第七类、第五类、第六类、第一类、第四类、第二类、第三类；而种核大小及形状变异系数从低到高依次为第六类、第二类、第七类、第一类、第三类、第四类、第五类。其中第七类包括7、72、81、36、28、67、74、80、65、11、16、23、39、98、12、68、38、64、97、103、82、91，共22个家系，果实大小及形状最为稳定，即均匀度高，其次是第五类；第六类的种核大小及形状最为稳定，均匀度高，其次是第二类。

关键词：苦楝；家系；性状变异；筛选

Different families of seed traits of Melia azedarach evaluation and screening

ABSTRACT

Geographic variation of germplasm resources around Melia azedarach in this study carried out research on the variation of the 96 families of Melia azedarach fruits and seed kernel traits, the variation of traits among families and within the family. The main conclusions are as follows:

1. provenances of 1000 grain weight, fruit size and seed size were significantly different, the weight is higher than the average of 24 families, accounting for 25%, fruit length is higher than the average of 41 families, accounting for 42.71%, higher than the average fruit width of 29 families, accounting for 30.21%, nuclear grown on the mean 43 families, accounting for 44.79%, higher than the average width of nuclear families with 31, accounting for 32.29%.
2. the coefficient of variation among families from high to low weight, fruit width, fruit length, kernel width and kernel length, kernel shape coefficient, coefficient of fruit shape; coefficients from high to low nuclear length, kernel width, kernel shape coefficient, fruit length, fruit width, fruit shape coefficient. There were 52 families with less coefficient of variation in fruit length, 52 families below the width variability coefficient, 59 families below the coefficient of variation in nuclear length, and 57 families below the nuclear width variability coefficient.

(3) cluster analysis of nuclear shape index, fruit weight / based on 96 families will be divided into 5 categories, the first group of families showed grain weight, fruit size, nuclear size medium; second groups of family 1000 grain weight, fruit, kernel, kernel, nearly round fruit the circular; third taxa, 1000 grain weight, fruit, and nuclear size is very small, while the fruit shape coefficient and kernel shape coefficient is the biggest performance for the most slender; family 1000 grain weight of fourth taxa slightly higher than third and fifth, and the fruit length is less than third and fifth kinds of fruit, fruit shape and width is opposite. The nuclear shape coefficient and the first class; fifth groups of small fruit length, 1000 grain weight, seed slender.

(4) cluster analysis of nuclear shape index and coefficient of variation of fruit / based on 96 families will be divided into 7 categories, fruit size and shape coefficient of variation from low to high order seventh class fifth, class sixth, first class fourth, second class, third class; and nuclear size and the shape coefficient of variation from low to high order sixth class second, class seventh, first class third, class fourth, class fifth. The seventh group included 7, 72, 81, 36, 28, 67, 74, 80, 65, 11, 16, 23, 39, 98, 12, 68, 38, 64, 97, 103, 82, 91, a total of 22 families, the most stable fruit size and shape, namely uniform the degree is high, followed by fifth; the most stable sixth types of nuclear size and shape, high uniformity, followed by second.

Key words：Melia azedarach; family; genetic variation; screening

目 录

引言 1

1 研究概况 2

1.1林木地理变异研究 2

1.2林木种源试验 3

1.3苦楝地理变异与遗传改良研究 3

2 材料与方法 6

2.1供试家系 6

2.2果实的处理 6

2.3果核、种子表型性状测定 6

2.4数据统计分析 7

3 结果与分析 8

3.1不同家系苦楝种子千粒重差异分析 8

3.2不同家系苦楝果实形状差异分析 8

3.3不同家系苦楝种核形状差异分析 10

3.4不同苦楝家系果实/种核形状聚类分析及优良家系筛选 12

3.4.1基于千粒重及果实/种核形状指标的优良家系筛选 12

3.4.2基于果实/种核形状指标变异系数的家系筛选 15

4 讨论 18

5 结论 19

致 谢 20

参考文献 21

引 言

苦楝在我国分布广泛，南至海南崖县，北到河北保定和山西运城、陕西渭南、甘肃陇南地区，东自台湾、沿海各省，西到四川、云南保山。苦楝分布范围十分广泛，不同群体长期受不同环境条件的影响和基因交流的限制，在自然选择与生态适应过程中，群体间在各种性状上会发生遗传分化。种子形态是树木一种较稳定的性状，是树木分类及遗传研究的重要指标，种子大小在同一植物种内或品种内被认为是相对稳定的，而在种群内、种群间甚至个体间，种子的大小会有差异。研究苦楝果核和种子性状的变异对于认识该物种的群落演替和种群更新、生态适应过程和系统发育过程具有重要意义。早在上世纪50年代就已开展过苦楝种源/家系试验，上世纪末和本世纪初也有苦楝种源/家系研究的报道，然而，参试种源/家系数量较少，多为局部种源试验。对于分布广泛的苦楝而言，采种点应具代表性并有足够数量，才能客观反映全分布区地理变异及其规律。本研究在我国苦楝全分布区采种，观测了96个单株的果实和种核性状及变异情况，旨在探明苦楝种实在家系水平的变异规律，为进一步开展苦楝优良家系选育，合理区划，科学地制定苦楝造林种子调拨提供科学依据。