15 research outputs found
Identification of a DNA marker linked to sex determination in Calamus tenuis Roxb., an economically important rattan species in northeast India
No full textRole of Root Traits and Root Phenotyping in Drought Tolerance
No full textThe spatial distribution of all root parts in a particular growth environment is collectively referred to as root system architecture (RSA). Root length, cortical cell file number, number of roots and cell size help in determining water uptake ability among various root types as an adaptation strategy under dry conditions. Using a combination of root phenotyping techniques that include laboratory, greenhouse, and field evaluations, root characteristics can be identified and selected. Roots play a significant role in the plant\u27s capacity to recover from drought stress. Root attributes are influenced by environmental factors, are difficult to measure in the field, and are regulated by polygenes. Different root properties, including root number, root length, root angle, and root surface area, have quantitative trait loci that have been found. Crop yield and the efficiency with which nutrients and water are used could both be improved genetically by improving the root system architecture in drought-prone areas. Different alleles may be introduced into elite cultivars to create desired root phenotypes through molecular breeding in order to ensure crop productivity in a harsh environment
ESTIMATION OF BISMUTH. PART VIII. GRAVIMETRIC ANALYSlS WITH PHENYLARSONIC ACID
No full textESTIMATION OF BISMUTH. PART VIII. GRAVIMETRIC ANALYSlS WITH PHENYLARSONIC ACI
Status of Genomic Research in Non-basmati Aromatic Joha Rice of Assam
No full textMany natively adapted, aromatic, and high-quality rice landraces can be found in NE India. Among the different classes of cultivated rice varieties, Assam has a distinctive scented rice variety known locally as \u27joha,\u27 which is particularly popular among the region\u27s farmers. The aroma of joha rice is also thought to differ markedly from that of basmati rice. Genotype stability can be established through genetic variation. Thus, new disease resistant joha rice varieties are necessary to meet both domestic and worldwide demand. There is a need for conservation of this traditional aromatic joha rice germplasm which could be used in the future breeding programme for multiple disease resistance and grain and aroma quality traits improvement. The recent advancements in marker and genomics assisted breeding coupled with high-throughput genotyping and phenotyping enable the discovery of novel alleles and gene targets for the implementation of sustainable rice cultivars with improved grain aroma quality
A Comparative Study on Nutritional and Biochemical Characterization of Banana Cultivars of Assam, India
No full textAn experiment was conducted in the Department of Horticulture, Assam Agricultural University, Jorhat to evaluate the huge diversity among the different banana germplasm in the state of Assam. The experiment comprised of 24 banana (Musa spp.) genotypes, of which the fruits were collected for precise biochemical characterization of the variations present in the collection. This analysis had created a database of the biochemical characterization of the fruits of different indigenous banana genotypes of Assam from which, it can be concluded that, there exists great genotype diversity among the Musa germplasm of Assam considering the fruit biochemical aspects and considerable amount of genetic variations are present even among the closely related genotypes within the same genomic group
Sorghum Physiology and Adaptation to Abiotic Stresses
No full textSorghum (Sorghum bicolor (L.) Moench) is the world\u27s fifth most important cereal and a staple crop for nations in Sub-Saharan Africa and Asia, with great biomass production potential. In the dry and semi-arid tropics, it may be considered as a source of human food, grain, and pasture for cattle, as well as fuel. Abiotic stress factors such as drought, warmth, salt, and submergence remain key limitations to crop growth and yield as a result of climate change. Although sorghum can resist a variety of conditions such as heat, drought, salt, and floods, in dry and semi-arid areas, this crop is typically damaged by water stress at the post-flowering stage. Drought tolerance is a result of morphological and anatomical characteristics (thick leaf wax, leaf rolling, deep root system, and kranz anatomy), as well as physiological responses such as osmotic adjustment via osmoprotectants, stay green traits, quiescence, and ROS-scavenging enzymes such as catalases (CAT), superoxide dismutase (SOD), peroxidases (POD), and ascorbate peroxida (APX). Drought resistance is enhanced by functional proteins such as aquaporin, late embryogenesis abundant (LEA) proteins, heat shock protein, and regulatory proteins such as protein kinase, various transcription factors such as DREB2, bZIP, and phytohormones such as ABA and ethylene. Drought-tolerant sorghum genotypes contain greater osmolyte, chlorophyll, RWC decrease, leaf rolling, and up-regulation of various enzymes and regulatory proteins. When breeding for drought resistance, it\u27s crucial to understand the various drought tolerance mechanisms in plants. The key to generating abiotic stress-tolerant agricultural plants in the future is to understand the physiological underpinning of crop production, crop responses, and crop adaptability in stress-prone locations under sustainable agriculture
Population Structure and Marker-Trait Association in Indigenous Aromatic Rice
No full textJoha rice of Assam is a class of rice with aroma, good cooking qualities and excellent palatability, which are grown in different places of Assam with their adaptability to local situations. A total of 143 simple sequence repeat markers were used in this study to reveal sufficient genetic variations among the 40 Joha and 14 non-Joha rice genotypes. Polymorphism information content of these markers were from 0.17 to 0.88, where the average of 3.7 alleles were observed. The model-based population assignment and dendrogram analysis identified three distinct groups in the 54 rice accessions, which established a clear identity of Joha accessions from the Basmati accessions, indicating high diversity and strong population structure in Joha rice. Furthermore, a total of 29 significant marker-trait associations (P < 0.05) for 10 characters were detected. The QTLs related with yield and grain quality can be used effectively in crop improvement programs and for further fine mapping and validation of specific genes to develop gene-based perfect markers in rice breeding and for mining of better alleles of these genes in Joha rice collections
Grain iron and zinc content is independent of anthocyanin accumulation in pigmented rice genotypes of Northeast region of India
No full textThe traditional rice genotypes of Assam are considered to have biological value due to the presence of several bioactive compounds like flavonoids, polyphenols, and anthocyanins, which have antioxidant, anti-cancer, anti-diabetic, and anti-aging properties. The pigmented genotypes are considered to have high iron (Fe) content. However, the effect of Fe and Zinc (Zn) accumulation on anthocyanin content is yet to be studied in pigmented rice of Assam. We studied the Fe, Zn, and anthocyanin content in grains of 204 traditional rice of Assam, which are traditionally preferred for their nutraceutical properties. We performed phenotypic and biochemical compositional analyses of 204 genotypes to identify those having high Fe, Zn, and anthocyanin. We also carried out the differential expression of a few selected Fe and Zn transporter genes along with the expression of anthocyanin biosynthesis genes. Interestingly, all pigmented rice genotypes contained a higher amount of phenolic compound than the non-pigmented form of rice. We found the highest (32.73 g) seed yield per plant for genotype Jengoni followed by Kajoli chokuwa and Khau Pakhi 1. We also listed 30 genotypes having high levels of Fe and Zn content. The genotype Jengoni accumulated the highest (186.9 μg g−1) Fe, while the highest Zn (119.9 μg g−1) content was measured in genotype Bora (Nagaon), The levels of Ferritin 2 gene expression were found to be significantly higher in Bora (Nagaon) (> 2-fold). For Zn accumulation, the genotype DRR Dhan-45, which was released as a high Zn content variety, showed significant up-regulation of the ZIP4 gene at booting (> 7-fold), post-anthesis (7.8-fold) and grain filling (> 5-fold) stages followed by Bora (Nagaon) (> 3-fold) at post-anthesis. Anthocyanidin synthase gene, Flavanone 3-dioxygenase 1-like (FDO1), and Chalcone-flavanone isomerase-like genes were up-regulated in highly pigmented genotype Bora (Nagaon) followed by Jengoni. Based on our data there was no significant correlation between iron and zinc content on the accumulation of anthocyanin. This challenges the present perception of the higher nutritive value in terms of the micronutrient content of the colored rice of Assam. This is the first report on the detailed characterization of traditional rice genotypes inclusive of phenotypic, biochemical, nutritional, and molecular attributes, which would be useful for designing the breeding program to improve Fe, Zn, or anthocyanin content in rice
