Response of Two Maize Populations to Reciprocal Recurrent Selection in a High-yield Environment

Abstract

A selection program using reciprocal recurrent selection procedures in maize (Zea mays L.) was developed. Intra-and interpopulation selection procedures were used for two maize populations BS10 and RSSSC. Intrapopulation selection procedures included phenotypic mass selection for multiple leaf and multiple stalk-rot disease resistance and S1 family selection for grain yield in a high-yield environment. Interpopulation improvement involved selection of testcrosses of S1 family×inbred tester in a high-yield environment. Evaluations of populations per Se, population crosses and populations×testers for response to three cycles of selection for grain yield were conducted at four environments. Evaluation of populations per se and population crosses for response to three cycles of selection for multiple leaf disease and multiple stalk-rot resistance was conducted at disease nursery in 1985. The results indicate that selection response was consistent among environments. Gain from selection was satisfactory in populations per Se, population crosses and populations x testers for grain yield, multiple leaf disease resistance and multiple stalk-rot resistance. Linear response to three cycles of selection for grain yield for BS10, RSSSC, BS10×RSSSC, BS10×B37, and RSSSC×B79 were: 0.95, 0.69, 0.65, 0.65 and 0.24 Mg/ha/cycle, respectively. The rates of gain for grain yield obtained in the present study compare favorably with published reports. Linear response for stalk lodging for BS1O, BS10×RSSSC and BS10×B37 were: -9.0, -5.4 and -3.5%/cycle, respectively. All populations per Se, population crosses and populations×testers showed significant increase in penetrometer reading. Increase in plant height and ear height were observed for RSSSC, BS10×RSSSC and RSSSC×B79. Population BS10 showed an increase in 300-kernel weight and kernel number per ear, and a decrease in ear number per 100 plants. Population RSSSC only showed an increase in 300-kernel weight. Three cycles of selection slightly increased grain moisture in BS10 and BS10×B37. This result indicates the procedures of selection in a high-yield environment are beneficial in improving grain yield, multiple disease resistance and stalk lodging resistance in maize populations per se and their hybrids.