RESUMEN
A field experiment was conducted during kharif, 2010 and rabi 2010-11 at Rice section, ARI, Rajendranagar, involving 7 parents, 7 F1 hybrids and their corresponding F2 populations to study the genetic parameters i.e. variability, heritabiity and genetic advance cross-wise in aromatic rice. A critical examination of genetic parameters in each cross in F2 generation revealed the presence of wider range of variability for both yield and quality traits. The estimates of heritability and genetic advance varied depending on the cross and also the character. Estimates of heritability in broad sense and genetic advance were high for number of grains per panicle, grain yield per plant and kernel length whereas, the estimates were relatively low-moderate for the remaining characters. Keeping in view the gene action known from the genetic parameters, selection on important yield components viz., number of grains per panicle and grain yield per plant and the quality trait, kernel length was suggested to bring out further improvement in aromatic rice. The crosses, RNR 2354 × Sye 632002 and YAMINI × BM 71 for number of grains per panicle, PUSA 1121 X MTU 1010 for grain yield per plant, PUSA 1121 × BM 71 and PUSA 1121× MTU 1010 for kernel length were identified as better crosses for further advancement to develop pure lines with high yield and quality.
RESUMEN
Plant stature of a rice crop is an important selection criterion. As plant height is a quantitative trait it is influenced by environmental conditions. A field experiment was conducted with 40 rice genotypes to assess the fluctuation and stability of plant height in a series of 16 environmental situations. The effects of genotype (G), environment (E) and all the components of G×E interaction were highly significant. Among the genotypes, Jamai sohagi was extremely sensitive (bi = 1.37) to environmental changes, and indicating lowest adaptability over the environments. Plant height of seven genotypes viz. Basmati PNR346, Benaful, BRRIdhan28, BRRIdhan38, BRRIdhan39, Gandho kasturi and Neimat, having the bi values between 0.59 and 0.72, showed high stability against environmental changes. The other seven genotypes viz. Badshabhog, Basmati Tapl-90, Kamini soru, Khazar, Laljira, Sarwati and Ukni madhu expressed only nonlinear sensitivity (S2 di = 90 – 181)) and thus unpredictable fluctuation. Twenty one genotypes indicated their average stability (bi = 0.91 -1.15) over the environments.