Ramgopal Laha’s research while affiliated with ICAR Research Complex for Eastern Region and other places

An essential element for healthy plant growth and development is phosphorus (P). Globally, lack of phosphorus (P) is a major factor affecting rice productivity. P insufficiency issues generally occur in iron-toxicity soils, soils with aluminium or manganese content, and acidic soils which accounts for over 80% of the area of land in North Eastern India. Also, 60–80% P of rice plants is deposited and stored in the form of phytate which also chelates the availability of Zn and Fe making them unavailable to human and monogastric animals and subsequently environmental pollution and eutrophication. To address the challenges to food and nutrition security, it is crucial to identify high P absorption ability from soil simultaneously reduced P in rice grains using available untapped plant genetic resources. In the present investigation, 96 rice germplasm were screened for phosphorous tolerance using Pup1 gene-based markers. Based on two markers (K46 and K20), only 15 genotypes (15.63%) were positive for PUP1 gene. Hydroponic treatment with low phosphorus revealed Mata Maha and Chakhao Lamhing as the most tolerant genotypes to P deficiency. The correlation analysis found that P was significantly and positively correlated with Fe (0.551) and Zinc content with Fe (0.480). The range of P content was 0.27–3.78mg/g with an average of 1.81mg/g. Intriguingly, the PUP1 gene is also significantly associated with P content in grain by enhancing the P content which is an undesirable trait. However, Insatang Makokching rice genotype showed the least P content (0.27mg/g) in grain though the presence of the positive PUP1 gene. A single nucleotide substitution (G/C) in the eight-exon position of SPDT gene altering the amino acid glycine (G) to arginine (R) in Insatang Makokching rice genotype could be the reason for lowering P content via altering the function of the SPDT protein in node I of panicles. Therefore, convergent selection of PSTOL1 and SPDT genes in rice would enhance low phosphorus tolerance while reduced P grain content ensuring rice agricultural sustainability concerning to phosphorus fertilizers.

The loss of rice's genetic diversity caused by the replacement of landraces with superior cultivars in modern agriculture highlights the importance of genetic diversity assessment. Therefore, a set of 96 rice genotypes collected from different parts of Manipur, India was used for genetic diversity assessment in the present investigation. Nine agronomic characters and 60 simple sequence repeat (SSR) microsatellite markers were the keys to differentiate their genetic relationship. A correlation study reveals the positive relationship of plant tiller number with yield which can be used as a selection criterion for the improvement of yield. The SSR profile depicts the presence of 118 alleles in the rice genotypes studied. The STRUCTURE analysis could be able to group the 96 rice genotypes into two major clusters and further sub-clustering into four sub-clusters in Cluster-I while into three sub-clusters in Cluster-II. Analysis of molecular variance (AMOVA) resulted in more variation in within individuals than among individuals and less variation exists among populations. A marker-trait association analysis identified 31 SSR markers significantly associated with eight yield-related traits. These markers would be useful for the identification of novel genes/alleles and could be deployed as a key indicator of selection for a marker-assisted breeding program of rice.

Chakhao is a popular pigmented black rice variety with remarkably high anthocyanin content. Due to its susceptibility to various biotic and abiotic stresses, its production has remained low. Here, two genes, Pi54 blast-resistant and OsSPL14, high-yielding genes of rice, were pyramided in a Chakhao lan-drace by crossing with CR Dhan 307. From a total of 147 F 4 lines developed, 32 were identified with the positive alleles of both genes, of which 16 were black grain coloured, and their total anthocyanin content ranged from 30.19±2.19 to 240.31±2.62 mg 100 g-1 dried weight. Among these, ChM 68 F 4 line had the highest anthocyanin content (240.31 ± 2.62 mg 100 g-1 of powdered grain) with more 118.96 mg 100 g-1 anthocyanin than the recipient parent, CHK13 (121.35±3.32 mg 100 g-1), making it a promising line to be released as a high-yielding and durable blast-resistant Chakhao variety in Manipur. Crop Breeding and Applied Biotechnology 24(3): e47772437, 2024 Brazilian Society of Plant Breeding. Printed in Brazil http://dx.

Rice variety differentiation was based on morphological descriptors (DUS) before the advent of genomic and proteomic technology. DNA fingerprinting is becoming an important molecular marker approach because of its wide application in varietal protection, classification, and conflict settlement. In the present study, genetic diversity and variability among the 11 rice varieties of Manipur at the molecular level was studied using 42 SSR markers. The genotypic data of the SSR markers revealed four sub-populations. Cluster analysis indicated the close similarity between RC Maniphou 12 and RC Maniphou 15. To create a DNA fingerprinting database for 11 rice varieties, three separate multiplex PCR systems using different combinations of 11 polymorphic SSR markers based on amplicon size were successfully developed. These were able to distinguish the distinctness of all the eleven released rice varieties.

Rice variety differentiation was based on morphological descriptors (DUS) before the advent of genomic and proteomic technology. DNA fingerprinting is becoming an important molecular marker approach because of its wide application in varietal protection, classification, and conflict settlement. In the present study, genetic diversity and variability among the 11 rice varieties of Manipur at the molecular level was studied using 42 SSR markers. The genotypic data of the SSR markers revealed four sub-populations. Cluster analysis indicated the close similarity between RC Maniphou 12 and RC Maniphou 15. To create a DNA fingerprinting database for 11 rice varieties, three separate multiplex PCR systems using different combinations of 11 polymorphic SSR markers based on amplicon size were successfully developed. These were able to distinguish the distinctness of all the eleven released rice varieties.

The cross-linked pine resin hydrogels were prepared by in-situ grafting polymerization and cross-linking of acrylamide onto a natural pine resin followed by hydrolysis. Microwave initiated synthesis under the selected experimental conditions did not exhibit any significant improvement over the conventional technique. The optimization studies of various synthesis parameters, namely, monomer, crosslinker, initiator concentration, the quantity of water per unit reaction mass, particle size of backbone and concentration of alkali were done. The swelling behaviour of a pine resin-based hydrogel in response to external stimuli namely salt solutions, fertilizer solutions, temperature, and pH was studied. The pine resin hydrogel showed significant water absorbency in various environments. The effect of pine resin hydrogel on the water absorption and retention characteristics of soil and the soilless medium was also investigated as a response to temperature and moisture levels. The inclusion of pine resin hydrogel enhanced the water holding capacity of soil and soil-less media, showing that it has significant potential for diverse applications in moisture stress agricultural soil.

The dissipation nature of chlorantraniliprole, fipronil and deltamethrin residues was studied on cabbage and soil. The insecticides such as chlorantraniliprole fipronil and deltamethrin, residues were sprayed as foliar application twice at an interval of 7 days with the recommended doses of deltamethrin (12.5 g a.i./ha), chlorantraniliprole (10 g a.i./ha) and fipronil (50 g a.i./ha). The samples were taken randomly before the application of insecticides and 1 hour after the second spray of insecticides. The repeatability and reproducibility of the residue analysis method of cabbage were found to be 0.30 to 4.50% and 1.84 to 2.39% respectively for all the insecticides whereas that of soil samples ranged from 0.54 to 3.84% and 1.56 to 2.87% respectively for repeatability and reproducibility. The residues were below the detectable limit for all the insecticides at harvest time. The residues of fipronil were found to be more persistent than those of chlorantraniliprole and deltamethrin. Fipronil was found to persist up to the 7th day with a residue of 0.01 mg kg − 1 . However, the residues of chlorantraniliprole and deltamethrin persisted upto the 5th day i.e. 0.11 mg kg − 1 and 0.03 mg kg − 1 respectively. Observation revealed that the residues of chlorantraniliprole on the cabbage head dissipated over the course of time and an equally high degree of dissipation was observed. The residues of fipronil were also found to be persistent in soil upto 7th day (0.01 mg kg − 1 ) as compared to chlorantraniliprole and deltamethrin residues.

The objective of the present discourse is to raise awareness among pig farmers about various infectious diseases and disease conditions that can affect pigs. It aims to provide important information about the signs and symptoms of these diseases as well as strategies for prevention, control, and management. Key topics covered include characteristic signs, vaccination, deworming, and disinfection. By providing comprehensive information on economically important diseases, the discourse aims to empower pig farmers with the knowledge and tools necessary to protect the health and well-being of their pigs and ultimately enhance the productivity and profitability of their pig farming operations.