Central Tuber Crops Research Institute

About: Central Tuber Crops Research Institute is a facility organization based out in Thiruvananthapuram, Kerala, India. It is known for research contribution in the topics: Starch & Fermentation. The organization has 475 authors who have published 587 publications receiving 10285 citations.

Cytotaxonomic investigations to assess diversity and evolution in Amorphophallus Blume ex Decne. (Araceae)

Abstract: Karyomorphological studies in twenty five accessions of Amorphophallus collected from four biogeographic zones of India comprising of seven wild species and 18 morphotypes and wild relatives of A. paeoniifolius revealed differences in chromosome numbers. Three chromosome numbers viz., 2n = 28 for all the A. paeoniifolius accessions, A. dubius, A. smithsonianus and A. sylvaticus; 2n = 26 for A. bonaccordensis, A. hohenackeri and A. commutatus; and 2n = 3 × = 39 for A. bulbifer were recorded. Based on karyological characters, a scheme for the evolution of chromosome number in the species of Amorphophallus was framed. Zarco’s asymmetry indices revealed that the accessions T2 (A. bonaccordensis) and T3 (A. smithsonianus) are the more evolved species in terms of karyotype symmetry. According to the classification of Stebbins, A. bonaccordensis included in 3B category was the most asymmetrical and hence considered as most evolved. Amorphophallus paeoniifolius var. campanulatus with A1 = 0.40–0.43 appeared to be more evolved than A. paeoniifolius var. paeoniifolius based on Zarco’s asymmetry indices. Slight differences observed in the A1 values (0.1714–0.37) in the accessions of A. paeoniifolius var. paeoniifolius demonstrate the close relationship of the accessions. Among the A. paeoniifolius accessions, TF% varied between 35.34 % (GJ) to 43.6 % (K3-1) with TF% of 37.64 in T10. Taxa with asymmetric karyotype tend to have low TF% and accordingly cv. Gajendra (GJ) and cv.karunaikizhangu (T10) (both A. paeoniifolius var. campanulatus) having low TF% can be considered as highly evolved among the A. paeoniifolius accessions. UPGMA clustering based on five karyotypic parameters namely total chromosome length (TCL), average chromosome length (ACL), chromosome number, TF% and ratio of longest chromosome (LC) to shortest chromosome (SC) of the complement revealed two principal clusters at a Euclidean distance of 1.3 and such clustering pattern is in tune with the morphological data which leads to make a valid assumption that A. dubius may be the immediate ancestor of cultivated forms.

Genome-wide identification of Ran GTPase family genes from wheat (T. aestivum) and their expression profile during developmental stages and abiotic stress conditions

Abstract: Maintenance of growth is important for sustaining yield under stress conditions. Hence, identification of genes involved in cell division and growth under abiotic stress is utmost important. Ras-related nuclear protein (Ran) is a small GTPase required for nucleocytoplasmic transport, mitotic progression, and nuclear envelope assembly in plants. In the present study, two Ran GTPase genes TaRAN1 and TaRAN2 were identified though genome-wide analysis in wheat (T. aestivum). Comparative analysis of Ran GTPases from wheat, barley, rice, maize, sorghum, and Arabidopsis revealed similar gene structure within phylogenetic clades and highly conserved protein structure. Expression analysis from expVIP platform showed ubiquitous expression of TaRAN genes across tissues and developmental stages. Under biotic and abiotic stresses, TaRAN1 expression was largely unaltered, while TaRAN2 showed stress specific response. In qRT-PCR analysis, TaRAN1 showed significantly higher expression as compared to TaRAN2 in shoot and root at seedling, vegetative, and reproductive stages. During progressive drought stress, TaRAN1 and TaRAN2 expression increase during early stress and restored to control level expression at higher stress levels in shoot. The steady-state level of transcripts was maintained to that of control in roots under drought stress. Under cold stress, expression of both the TaRAN genes decreased significantly at 3 h and became similar to control at 6 h in shoots, while salt stress significantly reduced the expression of TaRAN genes in shoots. The analysis suggests differential regulation of TaRAN genes under developmental stages and abiotic stresses. Delineating the molecular functions of Ran GTPases will help unravel the mechanism of stress induced growth inhibition in wheat.

Incidence and identification of Cassava tuber rot caused by Phytophthora palmivora

Abstract: The occurrence of Cassava tuber rot in regions of Kolli hills, Kollam, and Kottayam of South India, causes major economic loss up to 70% in Cassava production. The disease tuber is characterised by brown watery lesions with foul smell, making it unfit for further use. The sporangia of the pathogen were oval and ellipsoid with a short pedicle. Identification of the isolate from these regions was also confirmed by ribosomal internal transcribed spacer (ITS) of rDNA region. The pathogen was highly aggressive when pathogenicity was tested. Based on morphological, pathogenicity and ITS sequences, the pathogen was identified as Phytophthora palmivora. Development of integrated disease management practices is essential to combat the disease. This is the first report recording the spread of Cassava tuber rot disease in regions of Kolli hills of Tamil Nadu and Kollam and Kottayam, of Kerala.