Transgressive segregations in two pea F₂ populations and their respective F_2:3 families

Segregações transgressivas em duas populações F₂ de ervilha e suas respectivas famílias F_2:3

Abstract:

The objective of this work was to evaluate the variability present in two pea (Pisum sativum) F₂ populations and their corresponding F_2:3 families, as well as to determine, in both generations, the frequency of transgressive segregants in order to isolate early superior families. The study was conducted from a cross of green pea varieties (Ilca 5115 and Turf) and a cross of yellow pea varieties (Zavalla 15 and Amarilla). In both generations, morphological traits were evaluated. Phenotypic and genotypic variances, experimental error variance, genotypic and phenotypic coefficients of variation, broad-sense heritability, and transgressive segregants were determined. The green F₂ population showed greater variation, whereas the yellow F_2:3 families had higher average values for most traits. In the green F_2:3 population, the percentage of transgressive segregants was greater or equal to 20, while, in the yellow one, no traits had a percentage greater than 20. High heritability values were obtained for most traits in both generations. Considering all traits, 45% of the transgressive segregants are found in the F₂ populations and 42% of the F₂ transgressive segregants in the F_2:3 generation. The distribution of F_2:3 families allows to select promising families according to the breeding program objectives.

Index terms:
Pisum sativum; genetic variability; heritability; principal component analysis