Crossability Relations of Domesticated Peas (Pisum sativum and Pisum abyssinicum) With Wild Pisum fulvum and Drought Response Assessment of P. sativum × P. fulvum Progenies

The productivity and quality of grain crops in semiarid environments is often affected by drought, which is likely to accentuate due to predicted climate changes. Wild pea (Pisum fulvum Sibth. & Smith) accessions are known to harbour useful allelic diversity for drought responses. The objectives of this study were: (a) assessment of the crossability relations between wild P. fulvum accessions and domesticated peas (Pisum sativum and Pisum abyssinicum) and (b) exploring the potential to enhance pea drought resistance with wild allelic variation. Interspecific crosses were made with domesticated cultivars as females and wild P. fulvum accessions as pollen donors. Interspecific hybrids were obtained with similar success rates in both combinations (P. sativum × fulvum and P. abyssinicum × fulvum). The genetic background of both the domesticated cultivars and the P. fulvum accessions affected the viability of the resulting F₁ hybrids as well as their capacity to produce normal F₂ seeds. Differential success rate among the studied P. fulvum accessions suggests the existence of more than one chromosomal linear order within the P. fulvum gene pool. Interspecific F₁ hybrids with P. abyssinicum showed higher values of pollen stainability (an indicator of genetic compatibility) than hybrids involving P. sativum, but the studied F₂ population exhibited an opposite trend, suggesting higher scopes for wild P. fulvum introgression into P. sativum. While the agronomic performance of interspecific F₃ and BC₁F₂ (P. sativum × fulvum) progenies under well-watered (control) conditions was similar to the domestic parent cv. Cameor, under water-limited (drought) conditions, some introgression derivatives showed three times greater productivity (total dry matter and grain yield) and significantly greater stability across water treatments, confirming the potential to introgress drought-adaptive alleles from P. fulvum into domesticated pea. The study refutes past hypotheses regarding the role of P. fulvum in the ancestry of P. abyssinicum and demonstrates the crossability potential between P. fulvum and the domesticated peas providing a proof of concept for the potential to introgress drought-adaptive alleles from P. fulvum into the domesticated pea gene pool.