Qualification and Utilization of the within a Landrace Genetic Variability.

In self-pollinated crops, genetic homozygosity of individuals within a landrace is taken as a matter-of-course. Hence, elite landraces constitute valuable sources to isolate single-plant progenies targeting pure-line varieties. Nevertheless, the negative relationship between yield and competitive ability may constitute an obstacle to recognize the most promising landrace and its outstanding genotypes. The performance of vetch and wheat landraces showed a perfect match to this speculation. They significantly lagged behind a homogeneous check at the dense stand, but the reverse was true with spaced plants to preclude interplant competition, indicating that landrace qualification as potential gene pool is a matter of absence of competition. Further, the hypothesis was verified through single-plant selection in the absence of competition within dry bean and lentil landraces. Breeding in bean was performed at both heat stressed (greenhouse) and normal conditions. Progeny-line testing at the above conditions revealed yield improvement up to 75% in the absence of competition and up to 38% at the farming density. Note of worthy is the hearsay evidence, drawn from growers, of exceptional performance even during fairly hot seasons. Breeding in lentil prioritized genotypes that escape infection from seed-born and insect-transmitted viruses. Ultra-low densities may not favor aphid plant-to-plant movement, however, favor insect landing and infections originating from outside sources, uncovering thus the susceptible genotypes. Second generation sister lines originated from healthy and highest yielding plants yielded up to 136 and 23% more than the source landrace as ultra-spaced and in dense stand, respectively. It was concluded that selection in the absence of competition improves the health status of the seeds produced and further results in potentially virus-tolerant varieties.

This research has been co‐financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) ‐ Research Funding Program: THALES. Investing in knowledge society through the European Social Fund.