Monday, 7 November 2005
11

Genotypic Variations in Prehavest Sprouting Resistance and Seed Dormancy in Barley.

Joseph Nyachiro, Jennifer Zantinge, James Helm, Patricia Juskiw, and Donald Salmon. AAFRD / FCDC, 5030 - 50 Street, Lacombe, AB T4L 1W8, Canada

Seed dormancy and preharvest sprouting resistance are important agronomic traits. The aim of this study was to evaluate spike sprouting resistance and seed dormancy in advanced breeding barley lines and determine the association between spike sprouting resistance and seed dormancy. Three intact spikes/plot from primary tillers were tested for sprouting resistance. Spikes were dried and stored in a freezer until tests were run at 18 ºC. Sprouting was rated on a 1 (non-sprouted) to 5 scale (100% sprouted) and ratings were converted to spike sprouting indices (SSI) accounting for spike sprouting promptness. Spikes were resistant to sprouting if the SSI ranged from 3.0 to 4.0 and very susceptible if >6.0. The seeds were germinated in Petri dishes at 18 ºC and >95% relative humidity for 8 days to test for seed dormancy using a weighted germination index (WGI). The SSI ranged from 3.0 to 8.6 and the WGI ranged between 0 (no seed germination) and 1 (100% seed germination). The WGI ranged from 0 to 1. The t tests of mean values showed significant (P > 0.01) differences for both WGI and SSI except for the SSI mean values of hulless and 6-rowed classes. The correlation between WGI and SSI (r = 0.37) was weak. The results indicated genetic variability among the barley breeding lines in both preharvest sprouting resistance and seed dormancy. Based on the SSI mean values the 6-rowed were similar to the hulless barley class. The WGI indicated more dormancy in 6-rowed compared with the 2-rowed and least dormancy in the hulless. The lack of a strong correlation between spike sprouting index and weighted germination index indicates that these parameters are independent of each other. The hull and seed per se do influence dormancy and the two factors can act together or independent of each other.

Handout (.pdf format, 97.0 kb)

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