Magnitude of heterosis for some quantitative traits in aromatic rice

Abstract

Measurement of heterosis is one among the strategies to achieve the targets in crop improvement, and serves as a guide in making sound decisions in selecting the best hybrids which could be commercially exploited and selected the desirable recombinants in the succeeding generations to develop new lines.  The best  heterotic effects on maturity was exhibited by  CL 1 x P 20, CL 1 x G 12, CL 1 x G 28 and CL 1 X G 10 as shown by their highly significant negative MP heterosis values of -6.2%, -6.85%, -7.41% and -9.01%, respectively and BP heterosis  with  -8.01%, -7.41%, -10.06% and -9.97%.  Heterosis in desirable direction was  noted on plant height  for  Jasmine x P20  over its BP (-8.83%). Heterotic effects on panicle length  was highly significantly differed and positively over  MP and in maximum  on Jasmine x G 28  ( 76.87%) and heterobeltiosis over the better parent in Kasturi x P 20 (21.13%). The positively significant MP heterosis for spikelet fertility was shown   by  CL 1 x G 28 (18.77%), Pandan x P 20 (18.39%), CL 1 x G 12 (17.40%), Pandan x G10 (16.76%) and CL 1 x P 20 (6.20%).  Most of the crosses had highly significant recorded in positive MP (2.58 to 34.55%) and BP heterosis  (6.00 to 30.12%) for 1000 seed weight.  CL 1x G 10, CL 2 x G 12 and Pandan  x P 20 revealed highly significant and positive MP   (138.55%, 88.90% and 81.23%) and BP heterosis (66.00%, 125.36% and 48.60%) for yield. CL 1 x G 10, CL 2 x G 12 and  Pandan  x P 20  would be forwarded in the next generation for identification and selection of transgressive segregants for yield; CL 1 x P 20, CL 1x G 12, CL 1 x G 20 and CL 1x G 10 for earliness; and  Jasmine x P 20 for dwarfness or shortness