Abstract
Lodging of pea plants has long been one of the greatest problems encountered at harvest, but it can be avoided with reduced plant height (PH) and increased number of tendrils. Two genes, Le (stem length), Psat5g299720, for PH, and Af (Afila), Psat2g173360, for semi-leafless types with multiple tendrils, were studied in the 6 most popular pea cultivars in Kazakhstan and in 60 pea accessions from a germplasm collection. ASQ molecular markers were developed based on an identified SNP in the Le gene. Two groups of 41 tall and 25 short (semi-dwarf) pea plants with average PHs of 83.6 and 56.3 cm, respectively, showed dominant and recessive Le alleles. Nine haplotypes of Af gene were found in the same set of pea genotypes and the PsPALM1b (Psat2g173360) gene was present in 48 pea plants with regular-type leaves, but it was absent (deleted) in 18 afila-type peas. Seed yields were assessed in the six major pea cultivars in field trials in the Akmola and Karaganda regions of Northern and Central Kazakhstan, respectively, during 2024 and 2025. The short and semi-leafless pea genotypes showed better results in favourable and wet conditions in the Akmola region, whereas tall pea genotypes with regular leaf types were more productive in drought conditions, realising their potential in the Karaganda region. The results for 60 pea accessions in the same regions in 2025 followed a similar trend. Finally, we concluded that drought can influence the significance of the lodging problem in pea genotypes in Kazakhstan, where an earlier start and faster growth of taller plants with regular leaves can become much more important traits for better drought tolerance and seed production.