Abstract:

In plant breeding， it is important to generate hybrids with sufficient phenotypic variation for germplasm innovation and variety improvement. In this study， we used the traditional hybridization method to cross Pennisetum purpureum ‘GM1’ （female parent） with the new line ‘F-B’ （male parent）， producing 536 hybrid offspring. We selected 150 representative F₁ lines for variation analysis， and performed hybrid identification and phenotypic variation analysis based on phenotypic traits and simple sequence repeat （SSR） markers. The main findings were as follows： 1） The F₁ generation showed greater phenotypic variation than the parents. Leaf length exhibited significant hybrid vigor and trait differences， with variation coefficients of 5.90%-21.05%； 2） Fourteen selected SSR primers amplified 219 clear bands， of which 118 were polymorphic， representing a polymorphism rate of 54.18%. The polymorphism information content value for SSR loci ranged from 29.59% to 44.63% （mean 35.40%）； 3） A cluster analysis based on phenotypic data grouped the hybrids into three categories， while SSR-based analysis divided them into four. The SSR-based analysis confirmed the maternal parent’s genetic dominance； 4） Specific primers accurately identified true hybrids with a 98% success rate. Most true hybrids had complementary parental bands， and some were the paternal-type. These results show that SSR analysis can reveal parental genetic information for the F₁ generation. Analyses based on phenotypic traits and 15 SSR core primers were able to effectively identify authentic hybrids among 150 F₁ hybrid progenies， highlighting materials that will be suitable for breeding new lines.

Key words: Pennisetum purpureum, F₁ hybrid progenies, hybrid identification, SSR molecular marker, phenotypic analysis, genetic diversity