Genetic Divergence Studies for Gall Midge Incidence, Earliness, Yield and Yield Components in Rice (Oryza sativa L.) Genotypes in Telangana State

Abstract

The study was carried out with 32 genotypes of rice (Oryza sativa L.) under irrigated system in RBD design with three replications at Agricultural Research Station, Kunaram in Telangana State during the rainy season of 2017. In general, major problem is high incidence of gall midge (Biotype 3) in rainy season under early as well as late planting conditions in Northern Zone of Telangana State. Hence, all the 32 genotypes were evaluated with an aim to know the divergence among them for gall midge incidence, earliness, yield and yield components. Based on D2 analysis, 32 genotypes were distributed into twelve clusters with the cluster I (12) containing maximum number of genotypes followed by cluster II (9). Highest inter cluster distances were observed between the clusters X and XII (2469.5) followed by III and XII (2283.3), and VII and XII (2173.6) suggesting wide diversity between the traits. Cluster mean analysis revealed that genotype, WGL 1119 from the cluster V would be used in breeding programme to develop gall midge resistant, high yielding, early duration, non lodging, medium slender grain genotypes as it recorded very low incidence of galls (0.9%) with high yield (4869.7 kg/ha), early duration (84.7 days), short stature (93.7 cm) and less 1000-grain weight (14.8 g). The genotypes, KNM 2305 and MTU 1001 from the clusters viz., VIII and X, respectively were identified as potential lines for developing high yielding, early and medium duration, long bold or long slender grain varieties. Among the traits studied, days to 50% flowering (55.8%) and 1000-grain weight (31.9%) manifested highest contribution towards total divergence, thus, these traits could be given due importance by the breeders for development of superior rice genotypes under crop improvement programme.

Genetic Variability, Heritability and Genetic Advance Studies on Yield, Its Components, Quality Traits and Gall Midge Incidence in Rice (Oryza sativa L.)

“…Low estimates of both parameters were found for hulling percentage indicating that non-additive genes may play a role in the inheritance of this trait and that breeding for heterosis or recurrent selection is preferable in order to improve such kind of trait. These results are in accordance with the findings of Srinivas et al [30] and Sreedhar Siddi and Anil Deva [20].…”

“…The mean performance of parents, crosses, and checks recorded on 14 characters is presented in Phenotypic and genotypic coefficient of variations (Table 4) showed that PCV values were higher than GCV values for all the traits indicating that environmental factors play a role in how these traits are expressed. The results of this study provided confirmation with Toshimenla and Changkija [14], Vanisree et al [15], Tuhina et al [16], Savitha and Usha Kumari [17], Bhinda et al [18], Siddi et al [19], Sreedhar Siddi and Anil Deva [20], Srinivas et al [21] and Subhas Chandra Roy and Pankaj Shil [22]. The GCV was found to be less than PCV for all the traits except for the number of productive tillers per plant.…”

Genetic Parameters and Divergence Studies for Gall Midge Incidence and Yield Components in Rice (Oryza sativa L.)

“…It might be due to their different genetic makeup from that of other germplasm lines in the present study. Similar results of greater genetic diversity for the genotypes in the monogenotypic clusters were also reported by Prasad et al (2021), Raju et al (2021), Siddi (2020), Srinivas et al (2016) and Mohan et al (2015).…”

“…These genotypes may be used for developing early and medium duration genotypes. Moreover, it was interesting to note that in most of the cases, cluster VII produced the highest inter cluster value with all other (Siddi, 2020).…”

“…Genetic divergence determines the inherent potential of a cross for hybrid vigour and frequency of desirable recombinants in subsequent generations. The pace and magnitude of genetic improvement are generally dependent on the amount of genetic diversity present in a population (Kumbhar et al, 2015, Prasad et al, 2021, Raju et al, 2021, Siddi, 2020, Srinivas et al, 2016, Mohan et al, 2015. For rational use of genetic resources, information on genetic diversity within and among closely related crop varieties is required (Raju et al, 2021).…”