Canadian Journal of Pure & Applied Sciences

Abstract: In plant breeding programs, potential genotypes are usually evaluated in different environments (locations and years) before desirable ones are selected. Genotype x environment (G x E) interaction is associated with the differential performance of materials tested at different locations and in different years, and influences selection and recommendation of cultivars. Highly stable genotypes are desirable. Performance and stability of grain maize (Zea mays L.) genotypes were evaluated at four locations in Peninsular Malaysia viz. Padang Rengas (Perak), Rhu Tapai (Terengganu), Sungai Udang (Melaka) and UPM, Serdang (Selangor), in two years. The objectives of this study were to evaluate the G x E interactions effects, and to identify high yielding genotypes at each location and their stability by using different stability parameters. The experiments at the locations were arranged in a randomized complete block design (RCBD) with four replications. Recommended agronomic practices were used at each location. Evaluations were conducted from June 2000 to March 2002. Genotype and G x E interaction effects were highly significant indicating high variability among genotypes, and genotypes responded differently to the changing environments. Among the 14 genotypes evaluated, GxA, Selected GxA, SC-2, Putra J-58 and TWC-4 revealed high performance and have good potential to be used as source populations for future breeding programs. Comparing performance of genotypes for grain yield and yield components, Selected GxA was found to have the highest grain yield (5726 kg ha-1), shelling percentage (84.9 %), 100-grain weight (25.5 g) and ear weight per plant (149.5 g), earliest in flowering (50.6 days to tasseling, and 53.2 to silking) and longest ears (15.5 cm). TWC-2 was found to be earliest to mature. SC-3 revealed the shortest plants, while Suwan 1 was the tallest and was late in maturity. The highest ear diameter was observed on SC-1. Terengganu in 2000 was found to be the most favourable environment, as shown by its highest environmental index. The stability analyses indicate that Selected GxA and DC-1 were identified as having the highest grain yields and the most stable. Some genotypes showed specific adaptability to specific locations, such as GxA in Perak, Putra J-58 in Terengganu and Selected GxA in Melaka and Selangor. This study has led to the identification and possible release of a new, high yielding and stable grain maize synthetic variety, Selected GxA, and a promising hybrid variety, DC-1.