Determining the breeding values of parental genotypes of sugarcane for biomass yield

Breeding values (BV) refer to the ability of a genotype to produce superior progenies and are used to predict the breeding performance of genotypes in sugarcane breeding. The objective of this study was to use best linear unbiased prediction (BLUP) to determine breeding values of parental genotypes for cane yield. Data were collected from a family (cross) evaluation (40 female, 26 male parents) trial planted in the Midlands region of KwaZulu-Natal, South Africa in 2013. The trial was planted in a randomised complete-block design with three replications per family. Cane biomass yield was estimated from stalk numbers, height and diameter measured from the first 20 progenies per plot. BLUP analysis, which provides comparison of genotypes with population means, was done using statistical analysis system software mixed models. There were significant variances in female (P=0.0003) and male (P=0.0145) results, indicating that large genetic variability among progenies was associated with parents. Genotypes that had significantly higher BV were: 00B1741 (6.35, P<0.0001), 82H0397 (5.71, P<0.0001), 90H0525 (2.21, P=0.0273), 85H0428 (2.81, P=0.0050), N52 (2.94, 0.0033), 01B0742 (3.98, P<0.0001), 95H0464 (2.43, P=0.0152) and 86H0437 (1.98, P=0.0473). Progenies generated from cross combinations of diverse parents with 00B1741 (+10%), 82H0397 (+16%), N52 (+16%) and 93H0460 (+26%), produced higher cane yields than the population mean. Genotypes N52 (16-38%), 82H0397 (26-35%) and 85H0428 (20-45%) when crossed with diverse parents from coastal, Midlands humic and sandy soil regions produced higher cane yields than the population mean suggesting broad general combining ability. Testing BV of genotypes with diverse populations is expected to identify parents suitable to breed for general adaptability and for use as tester parents in sugarcane breeding. Key words Breeding values, diverse parents, genetic variability, progenies