Caracterización fenotípica y genotípica del peso de grano en seis poblaciones de RILs de maíz

SANTIAGO ALVAREZ PRADO; LUCAS BORRÁS; VÍCTOR ABERTONDO; PATRICIO MAYOR; CHISTOPHER ZINSELMEIER; LYNN SENIOR

Rosario

Congreso; IX Congreso Nacional de Maíz y I Simposio Nacional de Sorgo; 2010

There is ample kernel weight (KW) variation among current commercial maize hybrids and inbreds. However, little is known about the genetic basis controlling this trait. In order to study this variability we constructed six RIL populations from four contrasting KW inbred lines using a connected structure. Our objectives were i) to phenotipically characterize the RIL populations that was developed, and ii) identified genome regions responsible for KW variability. We characterized the F4:5 and the F5:6 generations from the six bi-parental populations (totaling 1238 RILs) for KW. Kernel weight ranged from 73 to 348 mg kernel-1, and each population showed a normal distribution of KW frequencies in both generations. There were no differences (p<0.05) between generations, and there was a high correlation between them (r=0.72). The estimated character heritability was high (H2= 0.71). We detected 5 QTLs for KW. QTLs explained between 5 and 37% of KW variability. When we compared both populations, detected QTLs showed different localizations. Possible explanations could be QTL x background interaction or the number of molecular markers used in the analysis. Some of the QTLs detected in this work are in agreement with previously detected ones described in literature.