Genetic variability, heritability, genetic advance and phenotypic correlation in some onion varieties [electronic resource].

Includes references.

This study was carried out at Sids Research Station, Agricultural Research Center, Bani-Suef Govemorate during 2006/2007 and 2007/2008 seasons, to estimate genetic variability, heritability, genetic advance and phenotypic correlation in seven onion genotypes. These varieties were Giza 6 Mohassan, Giza 20. Composite 8. Composite 16, PUSS, Yellow Creol and Beth Alpha. The main results could be summarizes as follow: All the studied characters significantly affected by different cultivars. The highest means of bulb weight were recorded for composite 16 cultivar, while, the lowest means were recorded for Beth alpha cultivar in both seasons. The highest means of marketable yield / fed and total yield / fed were obtained by Giza 20 and composite 16 cultivars in the first and second seasons, respectively. The lowest means of bulb weight, marketable yield / fed and total yield / fed were obtained by Beth Alpha cultivar in both seasons. Weight loss % at 60 days exhibited the highest values of coefficient of phenotypic and genotypic variance in both seasons, while days to maturity and bulb weight exhibited the lowest values in the first and second seasons, respectively. The maximum estimates of heritability in broad sense (H2 bs) were obtained for dry matter% and plant weight, while the minimum ones were obtained for weight loss% at 120 days and culls yield, in the first and second seasons, respectively. Weight loss% at 60 days gave the highest values of genetic advance percentage (GS%) in both seasons, While days to maturity and bulb weight gave the lowest ones in the first and second seasons, respectively. Bulb weight had highly significant positive correlation with plant weight, dry matter% and TSS% in both seasons. The significant positive correlation was obtained between bulb weight and each of plant height and number of leaves/plant in both seasons. Marketable yield had highly significant positive correlation with plant height and total yield in both seasons. The significant positive correlation was obtained between marketable yield and each of number of leaves/plant, bulb length. dry matter% and TSS% in both seasons. Total yield had highly significant positive correlation with plant height, plant weight, days to maturity and marketable yield in both seasons. Significant positive correlation was obtained between total yield and each of number of leaves/plant. bulb length. dry matter% and TSS% in both seasons. The negative and significant correlation was obtained between total yield and weight loss% at 120 days in the second season.

Summary in Arabic.

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