Selection for Yield and Quality in Orchardgrass1
- J. S. Shenk and
- M. O. Westerhaus2
Progress in breeding for improved yield and quality in orchardgrass (Dactylis glomerata L.) is dependent upon genetic parameters and the number of outstanding entries that can be identified in a breeding program. This study was conducted with 101 late and 130 medium maturity clones selected to be vigorous and disease free from over 10,000 foreign and domestic clones. Clones were assigned into two groups (A and B) and further divided according to maturity (medium and late) to form four populations. Progeny were planted in several triple lattice designs and harvested three times each year. Samples of each plot were dried and ground for prediction of crude protein, in vitro dry matter disappearance, and neutral detergent fiber (NDF) by near infrared reflectance. Two selection indices, dairy herd selection index and relative feed value, were used to evaluate the progeny.
No consistent pattern of significant year × entry interaction was found for yield and quality traits over trials. Heritability estimates were low to medium (0.08 to 0.64) with the heritability quality traits (0.20 to 0.64) higher than for yield (0.08 to 0.61). Although a few significant negative genetic correlations were found, entries having both high yield and quality were identified. The range in traits was small but late progeny generally had the greatest range. Approximately 3 % of the progeny had both superior yield and quality traits. Identification of these superior entries was made easier by using a selection index.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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