Abstract:
Objective To elucidate the reproductive patterns of P. clarkii in the Nanning region of Guangxi and assess the genetic diversity of new strains obtained through mass selection breeding, thereby providing a scientific basis for improved variety selection and seed production.
Methods Monthly dynamic sampling over 12 months was conducted at the Runshuang P. clarkii breeding base in Datang Town, Liangqing District, Nanning City. Gonadosomatic indices (GSI) of male and female P. clarkii and berried cycle characteristics of females were systematically analyzed. Genetic diversity of three novel selective breeding lines (Egyptian, Yueyang-Hunan, and Qianjiang-Hubei populations) was evaluated using microsatellite markers.
Results Female gonadal development initiated in spring with low GSI (3.45±0.12)% peak in October, while males exhibited peak GSI in September (0.11%) and October (0.10%), indicating synchronized gonadal maturation.The new strains of P. clarkii obtained through mass selection and breeding for three generations all have relatively rich genetic diversity (expected heterozygosity, He 0.743–0.779; polymorphism information content, PIC 0.708–0.751), exceeding pre-breeding levels (F0). The Egyptian population (He 0.779, PIC 0.751) exhibited relatively high genetic diversity.
Conclusion Synchronized gonadal maturation peaks in October, and the new strain obtained through mass selection exhibited high genetic diversity. These findings provide critical data and theoretical support for P. clarkii genetic improvement and large-scale seedling production.
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