Browsing by Author "P. Mahadevu"

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Effect of blast disease on seed vigor parameters in rice
(Society for Plant Research, 2017) Varsha Gayatonde; P. Mahadevu; M.K. Prasanna Kumar; Prudhviraj Vennela
Blast (Magnaporthe oryza) is considered as one of the most important biotic stresses limiting rice production. In the recent years due to uncertain climatic factors blast is affecting even the popular landraces known to be resistant over a period of time. Present study is focused on the effect of the disease on seed germination and growth rate. The pool consists of 85 varieties, which include 38 released varieties, 43 landraces and four check varieties (Tadukan and Tetep- Resistant checks, HR-12 and CO- 39 susceptible). The experiment was laid out in Completely Randomized Design (CRD) with three replications. Results showed that 12 varieties showed minimal influence of blast disease. Five varieties- BI-33, Sannamullu, Mysur sanna, Ugibhatta and Jeerigesanna were susceptible under field condition but found with minimum losses in germination and seedling growth test. Therefore, the results clearly indicate that minimum to moderate influence can be observed by blast disease during germination and seedling growth stages. © 2017, SPR, All Rights Reserved.
Genetic diversity analysis and heterotic grouping of Indian white maize inbred lines using combining ability and SNP markers
(John Wiley and Sons Inc, 2024) Arushi Arora; Abhijit Kumar Das; Shubhank Dixit; K.R. Yathish; S.B. Singh; J.C. Sekhar; R. Ravikesavan; J.P. Sahi; I. Sudhir Kumar; P. Mahadevu; Digbijaya Swain; R.M. Kachapur; Mitchell R. Tuinstra; Sreya Venadan; Sujay Rakshit
Maize (Zea mays L.) is a versatile crop with high genetic yield potential and various uses. While yellow maize is primarily used for animal feed, white maize is preferred as a food by rural and tribal populations in India. However, white maize landraces suffer immensely in terms of low yield. Heterotic grouping is an excellent method to develop hybrids with increased yield potential in maize. The heterotic grouping of 78 white maize inbred lines was performed using combining ability and molecular diversity analysis. The lines were crossed with two testers, and the resulting hybrids were evaluated for grain yield at three locations representing different agroecological zones in India. The combining ability analysis based on specific combining ability effects on mean grain yield was used to classify the inbred lines into heterotic groups (HG-A: 18 inbreds; HG-B: 33 inbreds). Additionally, marker-based clustering using 62,470 single nucleotide polymorphisms (SNPs) generated through genotyping by sequencing was also employed to determine the genetic relationships among these lines. The combining ability information was superimposed on marker-based clustering data to obtain the heterotic grouping information, and two distinct HGs with 7 (HG-1) and 18 inbred lines (HG-2) were developed. The results of this study will contribute to the development of high-performing white maize hybrids through the efficient utilization of clear-cut and well-defined HGs. Hence, the use of SNP markers along with the combining ability of inbred lines is a useful method for heterotic grouping and understanding of genetic relationships of white maize. © 2024 The Authors. Crop Science © 2024 Crop Science Society of America.
Multi-location evaluation of mungbean (Vigna radiata L.) in Indian climates: Ecophenological dynamics, yield relation, and characterization of locations
(Frontiers Media S.A., 2022) Ashok K. Parihar; Sanjeev Gupta; Kali K. Hazra; Amrit Lamichaney; Debjyoti Sen Gupta; Deepak Singh; Raju Kumar; Anil K. Singh; Rakesh Vaishnavi; M. Samuel Jaberson; Sankar P. Das; Jai Dev; Rajesh K. Yadav; B.S. Jamwal; B.R. Choudhary; O.P. Khedar; Vijay Prakash; Harsh K. Dikshit; R.K. Panwar; Manoj Katiyar; Pankaj Kumar; C.S. Mahto; H.K. Borah; M.N. Singh; Arpita Das; A.N. Patil; H.C. Nanda; Vinod Kumar; Sumer D. Rajput; D.A. Chauhan; M.H. Patel; Raja R. Kanwar; Jitendra Kumar; S.P. Mishra; Hitesh Kumar; Indu Swarup; Suma Mogali; D. Kumaresan; Narayana Manivannan; M. Byre Gowda; Muthaiyan Pandiyan; Polneni J. Rao; D. Shivani; A.M. Prusti; P. Mahadevu; K. Iyanar; Sujata Das
Crop yield varies considerably within agroecology depending on the genetic potential of crop cultivars and various edaphic and climatic variables. Understanding site-specific changes in crop yield and genotype × environment interaction are crucial and needs exceptional consideration in strategic breeding programs. Further, genotypic response to diverse agro-ecologies offers identification of strategic locations for evaluating traits of interest to strengthen and accelerate the national variety release program. In this study, multi-location field trial data have been used to investigate the impact of environmental conditions on crop phenological dynamics and their influence on the yield of mungbean in different agroecological regions of the Indian subcontinent. The present attempt is also intended to identify the strategic location(s) favoring higher yield and distinctiveness within mungbean genotypes. In the field trial, a total of 34 different mungbean genotypes were grown in 39 locations covering the north hill zone (n = 4), northeastern plain zone (n = 6), northwestern plain zone (n = 7), central zone (n = 11) and south zone (n = 11). The results revealed that the effect of the environment was prominent on both the phenological dynamics and productivity of the mungbean. Noticeable variations (expressed as coefficient of variation) were observed for the parameters of days to 50% flowering (13%), days to maturity (12%), reproductive period (21%), grain yield (33%), and 1000-grain weight (14%) across the environments. The genotype, environment, and genotype × environment accounted for 3.0, 54.2, and 29.7% of the total variation in mungbean yield, respectively (p < 0.001), suggesting an oversized significance of site-specific responses of the genotypes. Results demonstrated that a lower ambient temperature extended both flowering time and the crop period. Linear mixed model results revealed that the changes in phenological events (days to 50 % flowering, days to maturity, and reproductive period) with response to contrasting environments had no direct influence on crop yields (p > 0.05) for all the genotypes except PM 14-11. Results revealed that the south zone environment initiated early flowering and an extended reproductive period, thus sustaining yield with good seed size. While in low rainfall areas viz., Sriganganagar, New Delhi, Durgapura, and Sagar, the yield was comparatively low irrespective of genotypes. Correlation results and PCA indicated that rainfall during the crop season and relative humidity significantly and positively influenced grain yield. Hence, the present study suggests that the yield potential of mungbean is independent of crop phenological dynamics; rather, climatic variables like rainfall and relative humidity have considerable influence on yield. Further, HA-GGE biplot analysis identified Sagar, New Delhi, Sriganganagar, Durgapura, Warangal, Srinagar, Kanpur, and Mohanpur as the ideal testing environments, which demonstrated high efficiency in the selection of new genotypes with wider adaptability. Copyright © 2022 Parihar, Gupta, Hazra, Lamichaney, Sen Gupta, Singh, Kumar, Singh, Vaishnavi, Jaberson, Das, Dev, Yadav, Jamwal, Choudhary, Khedar, Prakash, Dikshit, Panwar, Katiyar, Kumar, Mahto, Borah, Singh, Das, Patil, Nanda, Kumar, Rajput, Chauhan, Patel, Kanwar, Kumar, Mishra, Kumar, Swarup, Mogali, Kumaresan, Manivannan, Gowda, Pandiyan, Rao, Shivani, Prusti, Mahadevu, Iyanar and Das.
Study of suitable culture media and other abiotic factors for the growth and sporulation of Magnaporthe Oryzae
(EM International, 2016) Varsha Gayatonde; P. Mahadevu; Prudhvi Raj Vennela
In the present investigation the effect of media, photo-periods and isolation techniques influenced on mycelial growth and conidial production of M. oryzae were studied. Rice straw agar and oatmeal agar were found to be suitable for culturing different isolates of M. oryzae. Colonies of M. oryzae appeared white on oat meal, whitish grey on rice agar and grey on potato dextrose agar. When spores of 26 isolates were compared, MTU 1010 and Karidoddi showed the maximum size of conidia whereas isolate Kempudoddi showed minimum size of conidia. Size of the conidia from the infected samples varied from 13.8-21.35 urn to 2.7-7.8 urn (L × B) in all isolates where there was no significant variation in shape of conidia. The spores of rice isolates collected from Ponnampet were smaller as compared to Mandya. Highest radial growth of mycelia on Sixteenth day was shown on three medias from three rice varietal isolates Viz, Kempudoddi (83.23 mm) on OMA, Gamnadabhatta (70.42 mm) PDA, Honasu (75.3 mm) on RSA.