Heiplanmi Rymbai | ICAR Reseach Complex for NEH Region (original) (raw)

Papers by Heiplanmi Rymbai

Indian Journal of Hill Farming, 2024

Citrus reticulata is one of the most important commercial fruit crops in north-eastern India. The... more Citrus reticulata is one of the most important commercial fruit crops in north-eastern India. The fruits are of premium quality with a unique taste due to the favorable agro-ecological conditions of the region. The demand for citrus fruits is increasing, providing enormous potential for future growth. The availability of certified citrus quality planting materials (CQPM) is the most strategic means to meet the desired growth and demand. Presently, there is a shortage of certified CQPM. Moreover, the citrus propagules are vulnerable to several pathogens, particularly viruses, viroid-like, and systemic bacteria, which are both graft- and vector-transmissible. Mechanisms are needed for an effective regulatory framework through accreditation and certification of mother stocks in the production of a certified CQPM. In this paper, a standard of procedures (SOPs) for the production of certified CQPM is discussed thoroughly. The major steps in the production of certified CPQM are: i) selection and identification of plus plants on the basis of two major criteria, i.e., horticultural traits and virus-free source plants; ii) maintenance of certified clean foundation stocks (Block 1); iii) multiplication of stock (Block 1); iv) labelling of certified CQPM with a unique bar or QR code for distribution. Periodic monitoring and maintaining the traceability records of a chain-of-custody of certified CQPM. Therefore, the strict adoption of a protocol will help in the production of the highest horticulturally superior plants and pathogen-free for the sustainable performance of citrus orchards in terms of tree longevity, fruit yield, and quality.

International Journal of Innovative Horticulture, 2024

The peel colour of fruit is one of the most vital quality elements that affects fruit marketabili... more The peel colour of fruit is one of the most vital quality elements that affects fruit marketability and consumer acceptability. Citrus early varieties and native species generally reach internal maturity with minimum eating quality prior to the onset of colour break, i.e., when the natural colour development is relatively weak and insufficient. Similarly, to avoid any weather inclement or to extend the market, the fruits were harvested early with poor appearance. In such cases, degreening techniques were used to accelerate the colour transition of fruits from green to a desirable colour and to enhance their marketability. Exogenous ethylene degreening has effectively accelerated the external colour development of fruits by triggering ripening-related processes, most notably the breakdown of chlorophyll pigments and the accumulation of carotenoids in citrus peel tissue. The majority of citrus varieties respond favourably to preharvest degreening with ethephon; however, post-harvest degreening is commercially followed in citrus. The major factors affecting degreening processes are the preharvest factors (including fruit maturity stages, tree vigour, climatic effects, and cultural practices) and the post-harvest factors (i.e., atmospheric conditions and packinghouse treatments). The ethylene degreening exposure not only results in desirable appearance and quality improvements to fruit, but it may also have adverse consequences associated with hastened fruit senescence. However, the sensitivity of fruits to calyx senescence varies according to the variety, preharvest situations, and processing characteristics. Therefore, the degreening needs to be carried out in the correct environment for a desirable quality.

Frontiers in plant science, Apr 4, 2024

Journal of plant nutrition, Jan 29, 2024

Mandarin fruits are the most widely grown citrus fruits in the world, particularly in the eastern... more Mandarin fruits are the most widely grown citrus fruits in the world, particularly in the eastern Himalayas of India, which is the primary center of citrus diversity. Diagnosing potential nutritional imbalances using leaf tissue analysis is a mandatory practice for a higher yield. Regarding the nutritional diagnosis of Khasi mandarin plants, particularly in the acidic soil of the hilly ecology of the Eastern Himalayas, India, there is currently no information available. Therefore, the present study was conducted to identify nutrient constraints, establish leaf-based diagnostic recommended and integrated system (DRIS) norms, and determine nutrients' relationship with fruit yields in 144 orchards. The result showed that the DRIS indices predicted a nutritional optimum value for Khasi mandarin: 2.26-2.83% N, 0.11-0.16% P, 1.86-2.07% K, 1.85-2.12% Ca, 0.33-0.48% Mg, 170.10-225.10 mg kg −1 Fe, 74.03-83.43 mg kg −1 Mn, 1.24-2.45 mg kg −1 Cu, and 19.84-21.28 mg kg −1 Zn. The DRIS norms identified the nutrients Zn, P, Ca, K, N, and Mg as deficient to low levels (14.15!2.14), while Fe, Mn, and Cu were at high to excessive levels (5.50!18.25). The nutritional balance index had a significantly negative relationship with the fruit yield. Leaf nutrient concentrations of N (0.909 ��), P (0.827 ��), K (0.867 ��), Zn (0.833 ��), Ca (0.827 ��), and Mg (0.592 ��) had a significant positive correlation with fruit yield. The finding will facilitate the correct interpretation of leaf nutrient analysis, and the norms developed will enable a precise intervention through nutrient management for higher yields in mandarin citrus.

Genetic Resources and Crop Evolution, Aug 31, 2023

Researchers and consumers are highly interested in wild edible fruits around the world. Prunus je... more Researchers and consumers are highly interested in wild edible fruits around the world. Prunus jenkinsii grows in the wild and produces edible fruits, substantially contributing to the health, food, and livelihood of the people living in the eastern Himalayas, India. Although this species is extremely valuable, research on it is negligible. In

Plant Genetic Resources, Dec 20, 2023

A total of 32 sweet potato genotypes were evaluated to assess the genetic diversity based on quan... more A total of 32 sweet potato genotypes were evaluated to assess the genetic diversity based on quantitative traits and molecular markers, as well as stability for yield and related traits. Wider variability was observed for the traits like vine length (181.2-501.3 cm), number of leaves/plant (103.0-414.0 cm), internodal length (3.20-14.80 cm), petiole length (6.5-21.3 cm), leaf length (8.50-14.5 cm), leaf breadth (8.20-15.30 cm), leaf area (42.50-115.62 cm 2), tuber length (7.77-18.07 cm), tuber diameter (2.67-6.90 cm), tuber weight (65.60-192.09 g), tuber yield (7.77-28.87 t ha −1), dry matter (27.34-36.41%), total sugar (4.50-5.70%) and starch (18.50-29.92%) content. Desirable traits such as tuber yield, dry matter and starch content have shown high heritability (>60%) with moderate to high genetic advance. Under molecular analysis, a total of 232 alleles were observed from all 32 microsatellite markers, which ranged from 4 to 14 with an average of 7.77 alleles per locus. In the population, the average observed heterozygosity (0.51) was higher than the expected heterozygosity (0.49). The contribution of genotype, genotype by environment interaction to the total variations was found to be significant. Based on the multi-trait stability index (tuber length, tuber diameter, tuber weight and tuber yield), genotypes X-24, MLSPC-3, MLSPC-5, ARSPC-1 and TSP-12-12 were found to be most stable. Among them, the high-yielding and stable genotypes TSP-12-10 (26.0 t ha −1) and MLSPC-3 (23.9 t ha −1) can be promoted for commercial production or used as parental material in future crop improvement programmes.

Scientia Horticulturae, 2024

Guava (Psidium guajava L.) is an important fruit crop in the tropical and subtropical world. The ... more Guava (Psidium guajava L.) is an important fruit crop in the tropical and subtropical world. The morphological, biochemical, and molecular (using 56 microsatellite markers) characterization was carried out on 18 guava genotypes and related species (P. guineense) during 2018-2022. The present study exhibited a wider range of variability: fruit weight (61.5-68.4 g); fruit diameter (4.20-7.91 cm); total soluble solids (8.50-13.40 • Brix); titrable acidity (0.20-0.64%); reducing sugar (2.55-7.00 mg glucose /g); ascorbic acid (76.4-196.3 mg/100 g); total phenol (125.9-305.4 mg GAE/100 g pulp); and total flavonoid content (172.30-948.5 mg QE/100 g pulp). The antioxidant activities (FRAP and DPPH) showed a favorable relationship with ascorbic acid, total phenol, total flavonoid, and total flavonol content. Red-fleshed genotypes were found superior for all the quality parameters over white-fleshed genotypes. The molecular analysis generated 213 alleles from 56 markers, with 2-9 alleles per locus (mean = 3.80). Apart from the genetic diversity, the improved cultivars were also distinguished by a set of markers: RCGH-4 (mPGCIR-184 and mPGCIR-194); RCGH-1 (mPGCIR-108 and mPGCIR-243); RCG-11 (mPGCIR-206 and mPGCIR-325); and RCGH-7 (mPGCIR-16 and mPGCIR-19). The cluster analysis indicated that P. guineense was the most diverse of the cultivated species, and all the red flesh genotypes were close to each other. Furthermore, RCG-11 had a lower seed content (58.89 per 100 g pulp), while RCGH-1 and RCGH-4 were stable for fruit weight and seed number, which can be promoted for commercial production and future crop improvement programs.

Frontiers in Plant Science, 2024

Northeastern states of India are known for unique landraces of Capsicum spp. with geographical in... more Northeastern states of India are known for unique landraces of Capsicum spp. with geographical indications. However, little information is available about these valuable landraces of chillies. Surveys and collections were carried out in niche areas to find out their ecology and diversity through morphological traits and molecular analysis using microsatellite markers. Our result characterized the ecology of niche areas as cool (11.0°C–20.7°C) and humid (>60% relative humidity) climates for dalle-chilli (Capsicum annuum L.); mild-warm (12.2°C–28.6°C) and humid for king-chilli (C. chinense Jacq.); and cool to warm (11.3°C–33.1°C) and humid for bird’s eye chilli (C. frutescens L.) during the crop period. The canonical correspondence analysis has shown the significant impact of temperature on the agro-morphological traits and distribution of the landraces in their niche areas. A wide variability was observed for different quantitative traits and yield attributing characters (fruit length, diameter, weight, and yield), showing high heritability (97.0%–99.0%), and genetic advance as a percentage of the mean (119.8%–434.0%). A total of 47 SSR markers used for the molecular analysis generated 230 alleles, ranging from 2 (HPMSE-7) to 10 (HPMSE-5), with an average of 4.89 alleles per locus. The average polymorphism information content was also high (0.61) and ranged from 0.20 (HPMSE-7) to 0.85 (CAMS-91). The observed average heterozygosity was lower than the expected value. Analysis of molecular variance has shown significant variation within (69%) and between (31%) of the populations of Capsicum spp. Based on Nei’s genetic distance, bird’s eye chilli and king-chilli were found to be closer to each other, whereas dalle-chilli, a tretraploid species, was closer to hot pepper (C. annuum). However, the flower size of dalle-chilli was large and found closer to king-chilli in color and differs from C. chinense due to the presence of calyx teeth. For quality traits, landraces king-chilli, dalle-chilli, and bird’s eye chilli have shown 2.8, 2.0, and 1.4 times higher average capsaicin and 0.46, 0.25, and 0.22 times higher average oleoresin content over the hot pepper, respectively. The knowledge of ecology and diversity can be used in identifying new areas for production, selection of elite lines, conservation, and crop improvement.

Ama, Agricultural Mechanization in Asia, Africa & Latin America, 2024

This comprehensive study delves into the intricate dynamics of three Integrated Farming System (I... more This comprehensive study delves into the intricate dynamics of three Integrated Farming System (IFS) models implemented in the Ri-Bhoi District of Meghalaya, India, focusing on Marngar and Sarikhusi villager clusters under the Farmers' First Programme (FFP). Spanning the years 2017 to 2023, these models, designated as IFS I, IFS II, and IFS III, integrate various agricultural enterprises, including fishery, poultry, piggery, dairy, crops, goatery, and mushroom farming. The results reveal a remarkable transformation in the economic landscape for small and marginal farmers adopting these IFS models. In the case of IFS I, covering a 2.47-acre farm, the annual gross income surged from Rs. 1.73 lakhs to an impressive Rs. 6.23 lakhs post-intervention. IFS II, operating on a 1.4acre farm, showcased the effectiveness of integrating diverse enterprises. The model, incorporating piggery, fishery, poultry, duckery, crops, goatery, and mushroom farming, demonstrated a commendable average annual gross income of Rs. 3.60 lakhs. In the case of IFS III, which encompassed crops, fishery, poultry, and piggery on a 1.10-acre farm, the results indicated an almost twofold increase in annual gross income compared to the baseline. The benefit-cost ratio for IFS III was calculated at 2.38, affirming its profitability. The implications of these findings extend beyond the specific regions studied. Policymakers and agricultural extension services can leverage these insights to design and implement similar interventions in diverse agro-ecological contexts, aiming to promote sustainable agricultural practices. The success of these IFS models suggests a scalable and replicable approach that could contribute to holistic agricultural development and poverty alleviation in various rural settings.

Organic Cultivation of Citrus (Citrus spp.). In: Organic Culture of Tropical and Subtropical Fruit Plants, 2024

Rymbai, H. 2024. Organic Cultivation of Citrus (Citrus spp.). In: Organic Culture of Tropical and... more Rymbai, H. 2024. Organic Cultivation of Citrus (Citrus spp.). In: Organic Culture of Tropical and Subtropical Fruit Plants (Eds. Ghosh, S.N., Krishna Hare, Rymbai, H). Publisher Gyanavi Publishers & Distributors. ISBN978-81-960111-5-4. pp 131-176. doi: 10.13140/RG.2.2.36585.51049

Journal of Plant Nutrition, 2024

Plant Genetic Resources: Characterization and Utilization

Plant Genetic Resources: Characterization and Utilization, 2023

Gerbera is an important commercial flower crop in the world. Augmenting the genetic diversity is ... more Gerbera is an important commercial flower crop in the world. Augmenting the genetic diversity is desirable for further improvement in Gerbera breeding programme. Thirty-seven (37) Gerbera accessions were evaluated and analysed for genetic variability, heritability, correlation and path coefficient analysis using yield and quality traits. Results showed that phenotypic coefficients were higher than genotypic coefficients of variation for all the characters. All the traits, except stalk and flower diameter, had high heritability (>60%) and genetic advance (>20%). Based on cluster analysis, the 37 accessions were grouped into seven clusters. Cluster I consists of the maximum number of genotypes (22), while clusters IV–VII are monogenotypic with unique traits. Cluster analysis (D2) showed wider genetic diversity within and between the clusters. The first four principal components (Eigenvalue >1) contributed 72.3% of the total variation. The number of leaves, number of flowers a...

Heliyon

Seaweed extracts have shown profoundly positive effects on crop growth, quality and reproduction ... more Seaweed extracts have shown profoundly positive effects on crop growth, quality and reproduction in diverse agricultural and horticultural crops. Seaweed extracts can be used to promote the rooting and growth of cuttings in perennial fruit species like kiwifruit (Actinidia deliciosa). In this study, the cuttings were treated with 1, 5, 10 and 50% solutions of G Sap (Gracilaria edulis), K Sap (Kappaphycus alvarezii), AN (Ascophyllum nodosum), EM (Ecklonia maxima), HA (Humic acid) and control (water) for 6 h as base dipping. Subsequently, the treatments of G Sap, K Sap, AN, EM, HA and control were repeated every 15 days for a period of six months as application of 50 ml solutions in the potted cuttings. All the treatments exhibited significant effects on the rooting percent in all the kiwifruit cultivars, namely 'Monty', 'Abott', 'Hayward', 'Allison' and 'Bruno' (P ≤ 0.01) as compared to the control. Shoot and root growth parameters including leaf number per cutting, number of roots per cutting, number of branches, plant height, shoot diameter, root length, root diameter and root weight were all positively increased with the application of seaweed extracts (P ≤ 0.05). Cuttings treated with seaweed extract exhibited significantly higher levels of pigments (chlorophyll a, chlorophyll b and total carotenoids), metabolites (total carbohydrates and soluble phenols) and less electrolyte leakage as compared to the control cuttings. Significant positive and negative correlations were observed between biochemical parameters combined with plant nutrient concentration. Principal component analysis (PCA) revealed that PC1 and PC2 (first two principal components) accounted for 75% of the entire variation. While, PC1 accounted for 63% of the total variation, PC2 accounted for 11% of the total variation. The leaves and the roots of kiwifruit cultivar 'Hayward' treated with G Sap at 10%, K Sap at 10%, AN at 10%, EM at 10%, HA at 10% exhibited higher expression of all four root promoting candidate genes (GH3-3, LBD16, LBD29 and LRP1) compared to the control. Therefore, it can be concluded that, seaweed extract and humic acid can be used as a suitable alternative to synthetic hormones for promoting the rooting and growth of kiwifruit cuttings.

Journal of Ornamental Horticulture

Frontiers in Nutrition

The eastern Himalayas, one of the important hotspots of global biodiversity, have a rich diversit... more The eastern Himalayas, one of the important hotspots of global biodiversity, have a rich diversity of wild edible fruit trees. The fruits of these tree species have been consumed by the tribal people since time immemorial. However, there is limited information available on the biochemical and antioxidant properties of the fruits. Therefore, the present investigation was undertaken to study the physico-chemical and antioxidant properties of the nine most important wild fruit trees. Among the species, Pyrus pashia had the maximum fruit weight (37.83 g), while the highest juice (43.72%) and pulp content (84.67%) were noted in Haematocarpus validus and Myrica esculenta, respectively. Maximum total soluble solids (18.27%), total sugar (11.27%), moisture content (88.39%), ascorbic acid content (63.82 mg/100 g), total carotenoids (18.47 mg/100 g), and total monomeric anthocyanin (354.04 mg/100 g) were recorded in H. validus. Docynia indica had the highest total phenolic content (19.37 mg G...

Elaeagnus latifolia L., locally known as Sohshang is a very important fruit species among the tri... more Elaeagnus latifolia L., locally known as Sohshang is a very important fruit species among the tribes of Meghalaya. The fruit has been grown for its edible fruits and ornamental value since time immemorial. A study was carried out to find the variation among genotypes of the species during 2015-17. Result showed significant variation among genotypes (p ≤ 0.05). RCE-2 was found to produce highest fruit length (3.63 cm) and fruit diameter (2.84 cm), while, maximum fruit weight and edible flesh content was observed in RCE-2 (21.79 g) and RCE-1 (81.09%), respectively. RCE-2 produced maximum value for all seed characteristics. Total soluble solid was recorded maximum in RCE-4 (11.2%), titratable acidity in RCE-2 (4.03%), fruit juice pH in RCE-4 (3.7) and ascorbic acid in RCE-3 (15.03 mg 100 g-1 pulp). Similarly, a significant correlation was obtained among different physico-chemical traits. Fruit weight showed positive correlation with edible flesh (0.856**), seed weight (0.9210**), titratable acidity (0.867**), but negatively correlated with total soluble solid (-0.774*). Edible flesh had positive correlation with titratable acidity (0.903**) while had negative correlation with TSS (-0.878**) and ascorbic acid (-0.707*). Therefore, in view of the above, popularization of the crops is the need of the hour. Variation observed might be useful for selection of promising genotypes and inclusion as parental line in breeding programme.

Blooms of Gerbera for year-round prosperity

English & Hindi) BIBLIOGRAPHY i – xvii APPENDICES xviii – xxix

Whole-genome sequencing is at the cutting edge of life sciences in the new millennium. Since the ... more Whole-genome sequencing is at the cutting edge of life sciences in the new millennium. Since the first genome sequencing of the model plant Arabidopsis thaliana in 2000, whole genomes of about 100 plant species have been sequenced and genome sequences of several other plants are in the pipeline. Research publications on these genome initiatives are scattered on dedicated web sites and in journals with all too brief descriptions. The individual volumes elucidate the background history of the national and international genome initiatives; public and private partners involved; strategies and genomic resources and tools utilized; enumeration on the sequences and their assembly; repetitive sequences; gene annotation and genome duplication. In addition, synteny with other sequences, comparison of gene families and most importantly potential of the genome sequence information for gene pool characterization and genetic improvement of crop plants are described.