Selection in Sugarcane Germplasm under the Egyptian Conditions

Two hundred and ninety four sugarcane germplasm, collected from different geographical origins in the world were planted at Mattana Agricultural Research Station (latitude of 25° 17' N and longitude of 32° 33'), Luxor Governorate, Egypt for evaluation and selection of the best ones. Genetic variation and genetic advance were studied under very wide of genotypes variation. The experimental work was conducted at two stages. The 1st one (March, 2014) was to evaluate the 294 genotypes for cane and sugar yields in a randomized complete block design with three replications and to select the best ones, based on sugar yield with 5% selection intensity. The 2nd stage aimed to evaluate the selected genotypes from the 1st stage for yield and quality traits and to compare them with the two prevailed commercial variety GT54-9 and the new one namely G2003-47 for two years as a plant cane grown in 2015-2016 season and its 1st ratoon in 2016-2017, in a randomized complete block design with two replications. The results revealed highly variation among the evaluated 294 genotypes in all studied traits. High estimates of broadsense heritability (H %) were obtained for all studied traits, which ranged between 87.19% for brix and 99.82% for stalk length. All evaluated traits had high heritability estimates with high genetic advance values under 5% selection intensity, indicating the high probability of selecting individuals with better performance in the next stages. Results of the 2nd stage showed that cane yield, sugar recovery, sugar yield, purity, sucrose percent and stalk length were highly heritable characters in both plant and its 1st ratoon cane crops, while stalk diameter and stalk weight were highly heritable only in the plant cane and 1st ratoon, respectively. Genotypic coefficient of variation (GCV%) estimates were greater than 10% for stalk length, sugar recovery and sugar yield and reached 17.80% for stalk weight, indicating the presence of genetic variability and potential of selection for these traits. The overall mean of the two seasons pointed out to six genotypes showing the superiority in sugar yield/fad, which were: EH88/5-27 (8.78 tons/fad), SP72-5181 (9.58 tons/fad), G2008- 64 (10.13 tons/fad), G2008-20(10.50 tons/fad), G2007-61 (8.45 tons/fad), and G2006-36 (9.78 tons/fad) (fad = 4200m2) higher than that produced by the two check cultivars: GT54-9 (6.45 tons) and G2003-47 (8.43 tons/fad).