Winter Hardiness In Alfalfa Varieties

Author : Mindy Anne Weishaar
Publisher :
ISBN 13 :
Total Pages : 104 pages
Book Rating : 4.:/5 (538 download)

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Download or read book Improving Winterhardiness in Nondormant Alfalfa Germplasm written by Mindy Anne Weishaar and published by . This book was released on 2003 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improved winter hardiness in alfalfa is correlated with fall dormancy but the relationship is not completely understood. Our objectives were to determine how selection for improved winter hardiness influenced (i) fall height (ii) sugar, starch and protein concentration of roots and (iii) forage quality. Three cycles of selection for improved winter hardiness was conducted in Ames, IA using 'Magna 8', 'CUF 101', 'GT13R+', and '5939.' Seed from the second cycle of selection and parental cultivars were planted in rows in Ames and Nashua, IA in August 1999. Height was measured in October 1999 and winter injury was measured in April 2000. In May of 2001 seedlings from all three cycles of selection plus the parental cultivars and six check varieties were planted in Ames, IA and West Lafayette, IN. Height was measured in October 2001 and yield was measured at both locations in September and November. Plants were dug from half of each plot in November of 2001 and root samples were taken. Winter injury and winter survival were determined in April 2002 at both locations. In 1999 the C0 generation had a higher average height than the C2 generation for all four varieties at Ames, but only two varieties differed at Nashua. In April 2000 the C2 plants for all varieties had much higher winter injury values at Ames. The two C2 varieties did not have higher winter injury values at Nashua. In general there was no significant trend in autumn yield. A significant negative linear trend across all cycles and varieties was observed for height in October 2001. Among the laboratory traits, a positive linear trend in total sugars for all varieties was the only clear change noted. For forage quality traits, there was a significant linear trend in CUF101 for September crude protein and November NDF, ADF and crude protein. We have demonstrated that selection based solely on winter injury can dramatically improve winter hardiness in non-dormant populations, and while a concomitant decrease in autumn plant height occurred, autumn yield appeared to be unaffected.