Abstract:
Rice (Oryza sativa L.) is the staple food of over 21 million people of Sri
Lanka and it is mainly cultivated as a wetland crop in Sri Lanka. Regarding
grain yield in rice, more attention is paid to traits of above-ground plants.
However, without well well-grown fully functional underground portion,
plants cannot perform well. This study attempted to evaluate the root and
shoot morphology of the F₃ generation of four rice crosses under lower catena
soil conditions, and to identify better root characteristics of root
improvement in future breeding programs. In this study, progeny lines, which
include 320 lines derived from four rice crosses, along with their respective
parent plants and standard checks were tested in Randomized Complete
Block Design (RCBD) with 02 replicates. SAS and SPSS statistical software
used to compare the tested crosses data were analysed. Cross 2 (Ld 20-14-12
x Ld 20-15-14) and cross 4 (Ld 20-15-14 x Ld 20-22-04) were recorded
better morphological mean performance in root volume, root width, number
of roots, root dry weight, number of tillers, flag leaf length and width, number
of panicles, total panicle weight and seeds per panicle when compared with
their respective parents under lower catena soil conditions. So, cross 2 and
cross 4 have more potential to develop rice lines with better root structure in
future rice breeding programs. Overall comparison between the four crosses
recorded a higher Genotypic Coefficient of Variance (GCV%) and
phenotypic Coefficient of Variance (PCV%) for root morphology. Cross 1,
cross 2, cross 3 and cross 4 recorded significant positive correlations for
important root-related characteristics and other morphological
characteristics.
