Genotypic variation in seed germination in Stylosanthes seabrana.

摘要

The mature seeds of different genotypes of Stylosanthes seabrana (viz. IG 325, IG 339, IG 346, IG 352, IG 355, IG 369, IG 370, IG 384, IG 387, IG 391, IG 393, CPI 2523, CPI 2534, CPI 2539, CPI 408403, CPI 408404, CPI 408405, CPI 104710, CPI 105546B, CPI 110372) were harvested during November-December 2005 and stored in polythene bags (700 gauge) at room temperature in Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh, India. Seed germination study was conducted after 2 and 8 months of storage. The dormancy breaking seed treatments of concentrated H< sub>2SO< sub>4 for 4-5 minutes and then washing up in tap water for 15 minutes and scarification of seed through coarse sand paper were imposed. For germination, 25 uniform sized and healthy seeds of different genotypes were placed in sterilized petridishes lined with double layer Whatman filter paper moistened with distilled water (control). Genotypic variability was recorded with respect to the germination and vigour index among the genotypes of S. seabrana. Maximum germination was recorded in the seeds up scarified through coarse sand paper followed by concentrate H< sub>2SO< sub>4 (5 minutes) treatment. No germination was recorded in the seeds up to two months of storage, but it improved to 22% after 8 months of storage. Comparing the genotypic difference, maximum germination was recorded in IG 370 (95%) followed by IG 352 (94%), CPI 408403 and minimum in CPI 408405 (75%) after 8 months of seed storage. In some genotypes, the germination significantly improved by scarification seed treatments even after 2 months of seed storage, indicating that the hard seed coat was the major cause to induce the dormancy in stylo seeds. Vigour index was also improved by these dormancy breaking treatments. It is recommended that the seed scarification through coarse sand paper is the most easiest and economic dormancy breaking method for better germination in S. seabrana.