Agriculture College, Orissa University of Agriculture and Technology, Bhubaneswar
Grain shattering was studied in 12 early rice varieties both under field and laboratory conditions with special reference to inter-varietal and intra-plant variation. Correlation of grain shattering with certain quantitative characters affecting yield was also computed.
Field shattering varied from 1.5 per cent, in the low shattering Ptb. 10 to 8.7 per cent, in the high shattering N. 136. Existence of significant inter-varietal variation and a high heritability value indicated that shattering was controlled largely by genetic factors. Within a plant, the primary tiller exhibited less shattering than the main culm.
Grain shattering showed significant positive correlation with flowering duration, panicle length, number of grains per panicle and spikelet density and negative correlation with number of ear bearing tillers and panicle weight. Plant height did not show any association with shattering. Thus, non-shattering character could be combined with short plant height, short panicle and more number of ear bearing tillers.
Starch content in the spikelets in the high shattering N. 136 was comparatively low and reached a constant level 5 days earlier than that in the low shattering Ptb. 10. The observed differences with respect to starch content could probably be attributed to earlier formation of abscission layer at region of attachment of the spikelets to the pedicels in the high shattering N. 136.
