Genetic analysis and identification of molecular markers for Fusarium wilt resistance gene in Garden pea (Pisum sativum (L.) var. hortense)

Fusarium wilt, caused by Fusarium oxysporum f. sp. pisi, is a severe disease that
significantly impacts garden pea (Pisum sativum (L.) var. hortense) yields worldwide. This
study delves into the genetic basis of resistance to Fusarium wilt in garden peas, focusing on
identifying molecular markers associated with resistance genes. Genetic resistance is a more
cost-effective and environmentally friendly alternative to fungicide applications. Through
detailed genetic analysis, the study confirmed that resistance to Fusarium wilt is monogenic
and dominant. This was demonstrated by the segregation patterns observed in different
generations: F 1 (100% resistant), F 2 (124 resistant: 36 susceptible), and backcross
generations (BC 1 F 1 P 1 : 19 resistant: 16 susceptible; BC 1 F 1 P 2 : 35 resistant: 0 susceptible),
using 'GP-6' as the resistant parent and 'Arkel' as the susceptible parent. The resistance gene,
derived from the resistant parent 'GP-6', was characterized through phenotypic screening and
validated using molecular markers. The SCAR marker Y15_999Fw identified the 999 bp
band associated with resistance in 131 out of 160 F 2 plants. Additionally, the polymorphic
ISSR marker UBC-812 was found to be closely linked to the Fusarium wilt resistance locus,
exhibiting a 3:1 Mendelian segregation ratio in the F 2 population. Marker linkage analysis
placed UBC-812 at a distance of 5.01 cM from the resistance locus. These findings offer
crucial insights into the genetic mechanisms behind Fusarium wilt resistance in garden peas,
supporting the development of marker-assisted breeding strategies to cultivate wilt-resistant
pea varieties.