Confirmation of top cross hybrids in guava using morpho-molecular markers

english

2025

volume 121, issue 2

dissimilarity index   genetic diversity   molecular marker   polymorphism   segregates   top cross

Univerza v Ljubljani, Biotehniška fakulteta
(Obvezni izvod spletne publikacije)

The study was conducted to confirm the genetic diversity and hybridity of seventeen guava progenies developed from top-crossing between genetically distinct green and purple guava varieties. Morphological, biochemical, and molecular markers effectively identified hybrids exhibiting phenotypes from both parents. Moreover, remarkable genetic diversity was revealed among these segregants. Biplot analysis demonstrated a strong positive relationship between: (1) chlorophyll and anthocyanin content, (2) leaf length-to-width ratio, (3) leaf area, and (4) petiole length, identifying G15 and G16 genotypes as superior top-cross hybrids. A set of 10 simple sequence repeat (SSR) markers identified 36 alleles with a mean of 3.6 alleles per primer. The polymorphism percentage was 80.83 %, with pairwise dissimilarity ranging from 0.071 to 0.357. Four SSR primers (mPgCIR03, mPgCIR08, mPgCIR11, and mPgCIR19) specifically confirmed the top-cross hybrid status of G6, G8, G9, G10, G15, and G16 genotypes. These diverse genetic resources will be maintained for homozygous plant production through selfing and subsequent guava improvement programs.

19.01.2026