Plant Breeding Scheme Effects on The Flower Number and Grain Yield Components in Bread Wheat

Abstract

The increase of wheat production was mainly due to a considerable increment in growing areas and the improvements in grain yield through plant breeding programs. At present, ear analysis is one of the most relevant features in the development of new cultivars. The objectives of this study were to assess the effects of three cycles of recurrent selection of grain yield on the number of floret primordia and fertile florets per spikelet and to determine the relationship between grain number and the number of primordia and fertile florets. Forty eight families were evaluated in two running years (1997-1998) at the Ferreyra Experimental Station in COrdoba, Argentina (lat. 31° 29' S, long. 64° W). Five main shoots from each plot were divided in thirds for analysis. Results between cycles indicated that the most advanced cycle always had a higher mean value in the number of floret primordia per spikelet in 1997 than the values recorded for the other cycles. Statistical differences were observed in the number of fertile florets per spikelet between cycles in the lower and middle thirds both in 1997 and 1998. Significant differences were also observed in the kernel number per spikelet in the lower and upper third in 1998. Statistical analysis also showed that the number of floret primordia, fertile florets and kernels per spikelet increased mainly in the lower third during the microevolutive process. The mean values of all variables considered, regardless of cycle effects, were higher in the middle third than the other ones.