Development of a segregating population for QTL mapping in cotton (Gossypium hirsutum L.)

WINKLER HORACIO M.; LORENZINI, FERNANDO; RODRÍGUEZ, GUSTAVO RUBÉN; DILEO, PABLO N.; CEREIJO, ANTONELA E.; ROESCHLIN, ROXANA A.; PAYTAS, MARCELO J.; MUCHUT, ROBERTINO; SCARPIN, GONZALO J; SARTOR, G. J.

Congreso; Reunión Argentina de Fisiología vegetal; 2021

There are few commercial varieties of cotton availablein Argentina and consequently low genetic variability resulting in limitedyields and fiber quality. Thus, being necessary the development of newcultivars with improved agronomic characters that allow to be more competitiveworldwide. In this context, the generation of a segregating population (F2)from a contrasting parents crossing was carried out to obtain a population withhigh variability to be used in QTL mapping. Parent 1 (P1) with low lintpercent (LP), but high fiber quality (FQ) (length, strength and micronaire,among others), and parent 2 (P2) with high LP but low FQ were used. TheF2 population, together with the parents and F1, weresubjected to a phenotypic analysis of their agronomic characters where a highvariability was found for LP and FQ parameters. Broad sense heritability (h2)was estimated from the variance components of the non‑segregating generations(P1, P2 and F1) and the F2segregating generation. Levene´s test was performed to confirm homogeneousvariance in non-segregation generations, while normal distribution wasconfirmed with Shapiro-Wilks´s test. The h2 values were 0.83, 0.72,0.59 and 0.58 for LP, fiber length, micronaire and strength, respectively.These results show high ratio of total genetic variation (additive anddominance component) to the total phenotypic variation in the evaluated parameters.The agronomic characters analyzed, togheter with the identification ofpolymorphic molecular markers, through a statistical analysis will allow us toestablish an association between them and develop a QTLs mapping in the cottoncrop.