中华草龟(♀)与中华花龟(♂)及其杂种F_1代形态性状对体重的影响效果分析

F_1 Hybrid of Chinemys reevesii and Ocadia sinensis and the Effects of Morphological Characteristics on Body Weight

选择中华草龟、中华花龟及其杂种F1代幼龟共270只,测定了体重、背甲长、背甲宽、壳高、腹甲长等17个形态性状,采用相关分析、通径分析和多元回归分析研究了形态性状对体重的影响效果。结果表明,3种龟的测量形态性状与体重的相关系数均达到极显著水平(P<0.01);通径分析显示背甲长、背甲宽、壳高、腹甲长和甲桥长对体重的通径系数达到显著水平,它们是直接影响体重的重要性状,其中背甲长和壳高是影响体重的共同性状;决定系数分析结果与通径分析结果有一致的变化趋势;所选形态性状与体重的复相关指数分别为R2=0.945、0.920和0.958,表明影响体重的主要自变量指标已经找到;利用逐步回归分析方法建立了以背甲长、壳高和腹甲长,背甲长、壳高和甲桥长,背甲长、背甲宽和壳高等3种龟的多元回归方程,分别为:Y=-156.764+9.895X1+17.449X3+14.347X4,Y=-295.040+13.443X1+40.603X3+38.632X9,Y=-280.960+14.908X1+14.290X2+43.129X3。

The effects of morphological characteristics on body weight of hybrid turtle （ Chinemys reevesii ♀ × Ocadia sinen- sis ♂ ） and its parents were analyzed by using correlation analysis, path analysis and multiple regressions. Data of this study were collected from 270 young turtles. A total of 17 morphological characteristics including body weight （ Y）, carapace length （X1）, carapace width （X2 ）, body height （X3 ）, plastron length （X4 ）, etc. were measured. The results showed that there were significant relationship between the morphological characteristics and weight of＇the three measured turtles （P 〈 0. 01 ）. The path coefficient analysis revealed a truthful relationship between the independent variables and dependent varia- ble. Additionally, significant relationship were also observed between the path coefficients （ Pi ） of carapace length （X1 ）, carapace width （X2 ）, body height （X3 ）, plastron length （X4 ）, bridge length （X9 ） and body weight, and these character- istics are important for the determination of body weight, especially carapace length （X1） and body height （X3 ）. The trend of determination coefficients （ di ） was consistent with that of path coefficients （Pi）. The main variables were selected based on the result of high correlation index （R2 = 0. 945, 0. 920 and 0. 958）. The multiple regression equation for calculating the body weight of the three turtles were established as Y = - 156. 764 ＋ 9. 895X1 ＋ 17. 449X3 ＋ 14. 347X4, Y = - 295. 040 ＋ 13. 443X1 ＋40. 603X3 ＋38. 632X9 ,Y= -280. 960 ＋ 14. 908X1 ＋ 14. 290X2 ＋43. 129X3 , where Y is body weight, X1, X2, X3 , X4, X9 is carapace length, carapace width, body height, plastron length, and bridge length, respectively.