Browsing by Author "Rashmirekha Singh"

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Differential preference of grain of landrace and commercial rice genotypes to Sitophilus oryzae (L.) (Coleoptera: Curculionidae) attack
(Elsevier Ltd, 2024) Kamal Ravi Sharma; S.V.S. Raju; Sameer Kumar Singh; Rashmirekha Singh; Rajendran Dhanapal; Rakesh Kumar
The rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), is one of the most damaging pests to stored cereal grains worldwide. The current study aimed to clarify the relationship between S. oryzae development and the governing physicochemical grain properties. Laboratory experiments were conducted to determine the grain preference of various landrace and commercial rice genotypes to rice weevil. S. oryzae, findings divulged the low rates of adult emergence, low rates of grain consumption and high rates of mortality in the grain of rice varieties, HUR-3022 and Nagina-22. Conversely, S. oryzae adult emergence and grain consumption were found to be high in the grain of Swarna, Sathi, and Pusa basmati-1. Interestingly, the morphological and biochemical composition of the grain was the most important factor in determining resistant or preferred rice varieties to S. oryzae. Among the various physical characteristics investigated, grain hardness was found to have a significant and negative correlation with alive insect, grain weight loss, and preference index. On the other hand, protein and other biochemical grain characteristics were found to have a positive correlation with insect emergence, weight loss, and preference index. In particular, amylose (a key grain component) was found to have a negative correlation with weight loss and insect emergence. The findings of this study suggest that screening of different rice genotypes, for determining grain preference, may be a more viable option to minimize the grain losses during storage caused by S. oryzae. Moreover, the findings of present study could also help to formulate the breeding programs aimed at developing cultivars resistant to this notorious pest. © 2024 Elsevier Ltd
Evaluation of rice genotypes and varieties for resistance to white-backed planthopper, Sogatella furcifera (Horvath) (Hemiptera: Delphacidae)
(Malhotra Publishing House, 2024) Kamal Ravi Sharma; S.V.S. Raju; R.S. Meena; Sameer Kumar Singh; Rashmirekha Singh
Field screening of 50 genotypes and varieties of rice against white-backed planthopper revealed that rice genotypes IR82475-110-2-2-1-2, Akshyadhan, and MTU-1010 recorded minimum population and TN1, Swarna, MTU 7029, Baranideep and Sahbhagidhan showed maximum population of the pest. Rice genotypes Akshyadhan, HUR-105, Sathi and IR 96248-16-3-3-2B showed the lowest amount of total sugar in leaves while, IR82475-110-2-2-1-2, Akshyadhan, NDR-97 and IR 96248-16-3-3-2B recorded highest total phenol contents. However, the maximum per cent of crude silica content was observed in Akshyadhan, IR 96248-16-3-3-2B, and Pantdhan-12. The rice genotypes IR82475-110-2-2-1-2, Akshyadhan, MTU-1010 and IR-96248-16-3-3-2B exhibited fair degree of resistance to white-backed planthoppers. © 2024, Malhotra Publishing House. All rights reserved.
Rice genotypes and the biochemical basis of resistance against brown planthopper, Nilaparvata lugens (Stål)
(Association for Advancement of Entomology, 2024) Kamal Ravi Sharma; S.V.S. Raju; Sameer Kumar Singh; Rashmirekha Singh; R.S. Meena
Screening of 50 rice genotypes against brown planthopper infestation was conducted in open field conditions over two consecutive years (Kharif 2018-19 and 2019-20). Based on pest population per hill, rice genotypes IR82475-110-2-2-1-2,Akshyadhan, and MTU-1010 had the least brown planthoppers. TN1, Swarna, MTU 7029, Rajendra Kasturi, Baranideep, and Sahbhagidhan had the highest population and were classified as pest-prone. Rice leaf biochemical characteristics examined in selected genotypes, revealed that the pest population was significantly and positively correlated with total sugar (r = 0.608), crude protein (r = 0.306) and total free amino acid (r = 0.358), but significantly negatively correlated with phenol (r =-0.429), crude silica (r =-0.401), and tannin (r =-0.301). Correlation analysis revealed that susceptible entries contained more total sugar, crude protein, and total free amino acids, whereas resistant genotypes contained significantly more phenol, crude silica, and tannins. This study highlighted the significance of antixenotic properties in rice genotypes against brown planthoppers. © 2024 Association for Advancement of Entomology. © 2024 Association for Advancement of Entomology.