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.

Field experiments were conducted to evaluate the pre released rice genotypes under different sowing windows on clay soils of agricultural research station, Kunaram, Telangana state, India during two consecutive rainy seasons of 2018 and 2019.The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20thJune, 5thJuly and 20thJuly in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. The pooled data results indicated that, among the genotypes the genotype KNM 1638 sown on 5th July recorded maximum growth parameters and highest grain yield (7455 kg ha-1) and followed by sown on 20th June. In respect of economics of treatment combinations, the highest net returns (Rs.75,326 ha-1), gross returns (Rs.1,35,326 ha-1) and B:C (2.26) ratio were obtained when rice crop was sown during 5th July with the  genotype KNM1638 and followed by sown on 20th June with the  genotype KNM 1638.

The aim of this study was to investigate the effect of different sowing dates on growth and yield potential of pre released rice genotypes under irrigated conditions of Northern Telangana zone. The field experiments were carried out during two consecutive rabi seasons of 2018-19 and 2019-20, on clay soils of agricultural research station, Kunaram, Telangana state, India. The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20th November, 5th December and 20th December in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. Pooled data analysis results revealed that the different sowing dates and genotypes significant effect on all the studied growth and yield characters. The rice crop sown on 20th December recorded significantly  higher grain yield ( 8138 kg ha-1) and Among the genotypes, the short slender, short duration genotype KNM 733 recorded the recorded the maximum grain yield ( 8024 kg ha-1), which was on par with the other genotypes. The treatment combinations data results concluded that the, among the genotypes the genotype KNM 118 was recorded highest grain yield (8438 kg ha-1) when sowing was taken up on 20th December and followed by  the genotype KNM 733 with sown on 20th  November. In respect of economics of treatment combinations, the highest net returns (Rs.91,165 ha-1) and B:C (2.47)  ratio were obtained when rice crop was sown during 20th December with the  genotype KNM 118 and followed by sown on 20th November with the  genotype KNM 733.

Rice (Oryza sativa L.) is an important source of nutrition for the world’s burgeoning population that often faces yield loss due to infestation by the brown planthopper (BPH, Nilaparvata lugens (Stål)). The development of rice cultivars with BPH resistance is one of the crucial precedences in rice breeding programs. Recent progress in high-throughput SNP-based genotyping technology has made it possible to develop markers linked to the BPH more quickly than ever before. With this view, a genome-wide association study was undertaken for deriving marker-trait associations with BPH damage scores and SNPs from genotyping-by-sequencing data of 391 multi-parent advanced generation inter-cross (MAGIC) lines. A total of 23 significant SNPs involved in stress resistance pathways were selected from a general linear model along with 31 SNPs reported from a FarmCPU model in previous studies. Of these 54 SNPs, 20 were selected in such a way to cover 13 stress-related genes. Kompetitive allele-specific PCR (KASP) assays were designed for the 20 selected SNPs and were subsequently used in validating the genotypes that were identified, six SNPs, viz, snpOS00912, snpOS00915, snpOS00922, snpOS00923, snpOS00927, and snpOS00929 as efficient in distinguishing the genotypes into BPH-resistant and susceptible clusters. Bph17 and Bph32 genes that are highly effective against the biotype 4 of the BPH have been validated by gene specific SNPs with favorable alleles in M201, M272, M344, RathuHeenati, and RathuHeenati accession. These identified genotypes could be useful as donors for transferring BPH resistance into popular varieties with marker-assisted selection using these diagnostic SNPs. The resistant lines and the significant SNPs unearthed from our study can be useful in developing BPH-resistant varieties after validating them in biparental populations with the potential usefulness of SNPs as causal markers.

Recent predictions on climate change indicate that episodes of unseasonal rains, cold stress, and high temperatures are expected to impact rice production and productivity. To obtain consistent yield across diverse environments, a rice variety should have adaptability and stability to fit into various growing seasons and locations. In the present investigation, AMMI model was employed to assess the stability of nine rice genotypes of the early maturity group across two summer and rainy seasons. Combined analysis of variance expressed a significant genotype, environment and genotype × environment interaction for grain yield and days to 50% flowering. The study also suggested environmental effect as the greatest part of the variation, followed by genotypic and genotype × environment interaction effects for these traits. Biplots and statistics of AMMI identified that G1, G3 and G5 were the most stable and adapted high yielding rice genotypes, while G9, G4 and G6 appeared to be the most stable genotypes with earliness. Hence, these genotypes could be used as directly as varieties or as donors in future breeding programmes for improving rice productivity in the early maturity group after evaluation under multi-location trials.