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SIMULTANEOUS EVALUATION OF GRAIN SORGHUM A-LINES AND RANDOM-MATING POPULATIONS WITH TOPCROSSES
Abstract
Grain sorghum {Sorghum biocolor (L.) Moench} topcrosses from 19 A-lines crossed to six random mating populations were evaluated for general combining ability (GCA) and specific combining ability (SCA) effects. Topcrosses were produced by interplanting short rows of A-lines within each population isolation block. Six replications of a split-plot design with populations as whole plots and A-lines as subplots were grown at Mead, Nebraska, in 1979 and 1980 on a Sharpsburg soil (Typic Argiudoll). Data were recorded on seven traits. Significant differences were detected among A-lines and among populations for grain yield, plant height, flowering, tillering, and oil percentage and for 100-seed weight and protein percentage in A-lines. No genotype x year yield interactions were significant for either parental group. Significant A-line x population (topcross) interactions were detected for yield, height, and flowering, but individual wholeplot analyses tended to rank the A-lines similarly for yield. There were no significant topcross x year interactions for any traits. Based on GCA effects, A-line 'N37' and population 'RP1R' were determined to be the superior yielding parents. SCA effects ranked topcross '72LN3625' x 'NP7BR' as superior, but 'N37' x 'RP1R' had the highest yield mean. Topcrosses appear to be an efficient technique for preliminary evaluation of grain sorghum and should expedite development of superior germplasm. The procedure provides for early identification of superior A-lines, permits direct inbreeding of superior topcross progeny, and identifies populations in which to initiate inbreeding to develop superior lines for use in hybrids.
Subject Area
Agronomy
Recommended Citation
HOOKSTRA, GENE HOWARD, "SIMULTANEOUS EVALUATION OF GRAIN SORGHUM A-LINES AND RANDOM-MATING POPULATIONS WITH TOPCROSSES" (1982). ETD collection for University of Nebraska-Lincoln. AAI8217531.
https://digitalcommons.unl.edu/dissertations/AAI8217531