The effectiveness of artificial pollination in various representatives of the genus Pisum L.

Abstract

Wild relatives of cultivated pea (Pisum sativum L.) represent an important reservoir of alleles associated with resistance to biotic and abiotic stressors; however, their use in breeding programs is constrained by limited knowledge of their diversity and by difficulties in obtaining hybrids under field conditions. In this study, we evaluated the efficiency of interspecific hybridization among P. sativum, P. elatius and P. fulvum under field conditions, focusing on the effects of flower emasculation timing, parental genotype, and direction of the cross. Morphological characteristics of the parental accessions were used to facilitate hybrid identification based on seed-coat coloration in direct and reciprocal crosses. Two pollination approaches were compared: immediate pollination following flower emasculation and delayed pollination conducted 24 hours after emasculation.

Across combinations involving P. sativum, hybrid seed set (S/F index) was consistently higher when pollination was performed immediately after emasculation. Delayed pollination resulted in a marked reduction of hybrid seed production, likely reflecting both physiological constraints and high temperature stress during flowering. Reciprocal crosses revealed low and relatively uniform hybridization efficiency in combinations with P. fulvum, whereas crosses involving P. elatius produced substantially higher seed set, consistent with its close genetic affinity to P. sativum. The stability of hybridization efficiency across years (2020 – 2021) was confirmed for several cross combinations. Evaluation of the F₁ and F₂ seed lots demonstrated the successful production of true interspecific hybrids, with diagnostic segregation observed in combinations where the wild species served as the maternal parent.

These results confirm that viable hybrids among representatives of the genus Pisum can be reliably obtained under field conditions and highlight that immediate post- emasculation pollination is the most effective strategy for maximizing hybrid seed production. The findings support the broader use of wild Pisum germplasm in pre-breeding and genetic research and provide practical recommendations for improving interspecific hybridization success in breeding programs.