白刺不同果实性状的遗传力估计及优良亲本选择

The Estimation of Heritability and Excellent Parent Selection of Nitraria tangutorum Fruit

亲子回归法研究白刺果实不同性状遗传力的结果表明，果径、果形、果色、果味、核形和果实出肉率等性状指标的遗传力较高，说明这些性状变异的遗传贡献较大，可作为白刺果实类型划分的主要指标，其中果径、果味和出肉率可作为白刺果实品质评价和优良亲本选择的主要依据。以果径和出肉率为指标，用家系选择法选择优良亲本可获得较大的遗传增益，且两指标选择的亲本一致，选择效果满意。

The heritabilities of different fruit characters of free pollinated family of Nitraria tangutorum were statistically estimated by using offspring parent regression. Based on a systematic survey to Nitraria tangutorum in Minqin county of Gansu, the nature fruits and seeds of selected 66 natural free pollinated families which represent the overall fruit variability of the species in this region are acquired. The main characters such as fruit size, shape, color, taste, fresh rate and sugar content are measured. Raising seedlings using collected seeds of different families was conducted to obtain the data of offspring of different families. Regression coefficient (b) was calculated by taking the parent data and offspring data as independent variable and dependent variable respectively, and the heritabilities (h 2 ) of different characters were estimated by using a formula: h 2=2b . The results showed that some fruit characters such as the minor diameter, shape, color, taste, fresh rate of fruit and dernel shape, were more heritable than other fruit characters, which indicated that the variations of these characters were controlled mainly by genetic factors, and the variation of other characters mainly by environmental factors. The more heritable characters as major indices can be applied to the classification of fruit form types of Nitraria tangutorum , of which the minor diameter, taste and fresh rate of fruit can be used to evaluate the fruit quality and select the excellent parents. Family selection (selecting rate 1/10) concerned with the minor diameter and fresh rate of fruit for selecting the excellent parents obtained larger genetic gains with 3 91% and 1 96% respectively, and the total fruit meat could increase by 6 2%. The selecting result was satisfactory.