Abstract:
Rice is the most important agricultural crop and staple food in Sri Lanka.
With the growing population and changing climatic conditions, it is
necessary to grow with increased yield potential. The objectives of this
research were to identify F₃ crosses exhibiting superior root and shoot
morphology, suitable for enhancing performance, and select superior plants
for F₄ generation evaluation in breeding programs aimed at root
improvement in upper catena conditions. A total of 150 progeny lines,
comprising four rice crosses, relevant parents and standard tests were tested
in a randomized complete block design with two replications. Data were
analyzed using IBM SPSS statistical software. In the tested four crosses were
recorded higher phenotypic coefficient of variance and genotypic coefficient
of variance values for the number of tillers, number of effective tillers, root
volume, root length, root width, number of roots, root dry weight, number of
panicles, total panicle weight and seeds per panicle. (Cross 3) Ld 20-11-3/
Ld 21-6-18-2 cross showed better mean performance for plant height, culm
height, flag leaf length, flag leaf width, root volume, root length, panicle
length, no of panicles, total panicle weight, seeds per panicle. (Cross 4) Ld
20-15-14/ Ld 20-22-4 cross showed better mean performance for, no of
tillers, no of effective tillers, root width, no of roots, and root dry weight.
Among the four rice crosses, crosses 3 and 4 showed better growth, yield
performance and root performance, therefore crosses 3 and 4 have the
potential to develop rice lines with better root structure in future rice breeding
programs.
