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.

Purification and identification of an antibacterial protein from the symbiotic bacteria associated with novel entomopathogenic nematode, Rhabditis ( Oscheius ) sp.

Abstract: Entomopathogenic nematodes (EPN) belonging to the families steinernematidae and heterorhabditidae and their symbiotic bacteria Xenorhabdus and Photorhabdus are well-known as biological control agents and are found to produce a wide range of bioactive secondary metabolites. Studies carried out at the Central Tuber Crops Research Institute (CTCRI) on entomopathogenic nematodes resulted in the identification of novel EPN belonging to the family Rhabditidae. This study reports the purification of a high molecular weight antibacterial protein from culture filtrates of a bacterium (Bacillus cereus) symbiotically associated with a novel entomopathogenic nematode Rhabditis (Oscheius) species, maintained at CTCRI laboratory. Fermentation conditions were standardized and optimum antibacterial activity was observed in tryptic soy broth after 48 h incubation at 30 °C. The aqueous extracts yielded antibacterial proteins which were purified by ammonium sulfate precipitation followed by ion exchange chromatography and size exclusion chromatography. Native gel electrophoresis indicated an active protein of molecular mass 220KDa which resolved into a major band of 90 kDa and a minor band of about 40 kDa on SDS-PAGE. The 90 kDa protein showed antibacterial activity and was further analysed by MALDI TOF—MS/MS. The protein was identified as a TQXA (Threonine–glutamine dipeptide) domain containing protein from Bacillus cereus. The protein was found to be active against Bacillus subtilis MTCC2756, Staphylococus aureus MTCC902 and Escherichia coli MTCC 2622 and was thermally stable.

Development of taro ( Colocasia esculenta (L.) Schott) hybrids overcoming its asynchrony in flowering using cryostored pollen

Abstract: Taro (Colocasia esculenta (L.) Schott) is an important root crop and vegetable across tropics and subtropics of the world. Conventional breeding of taro is hindered due to asynchrony in flowering owing to functional, structural barriers associated with flowering behaviour. An attempt was made to tackle asynchronous behaviour in taro by preserving pollen. The present study was therefore undertaken to cryostore taro pollen at different time intervals ranging from 1 week to 2 months and to use the cryostored pollen for hybridization of exotic taros introduced in India. Fruit setting was observed within a week of hybridizing exotic taros with cryopreserved pollens. Seeds extracted from different combinations were characterized. Seed germination in vitro was recorded in the range of 60–90 % among the seeds of different parental combinations. In vitro seedlings transplanted, hardened and established in screen house are now under field evaluation for early maturity and blight resistance. These results will improve planned hybridization in asynchronous flowering type aroids like taro and will contribute to recover desirable hybrids with the aid of cryopreservation tools.

Bio (Bacterial) Control of Pre- and Postharvest Diseases of Root and Tuber Crops

Abstract: The term “root and tuber crops” is a very general “catch-all” for a wide cross-section of subterranean storage organs of which there are approximately 38 root, 23 tuber, 14 rhizome, 11 corm, and 10 bulb crops. The most important among them are potato, sugar beet, carrot, onion, and garlic (temperate root and tuber crops) and cassava, sweet potato, yams, and aroids (tropical root and tuber crops). Pre and postharvest losses of these crops are very high and, depending on the species cultivated and the storage environment, may be of the order of 30–60%. Bacterial control has been emerging as a promising alternative to chemical fungicide to control many pre- and postharvest diseases of these crops. The underlying mechanisms include antibiosis, competition for nutrients and space, and systemic resistance. The various strategies for use of antagonists and field uses (i.e., seed treatment, soil application, foliar spray, antagonistic mixture) have been discussed. In addition, certain mechanisms to improve performance of antagonists, such as addition of nutrients, use of antagonist mixture, and formulation of antagonist have been emphasized in this chapter.

Physicochemical and Enzyme Susceptibility Characteristics of Starch Extracted from Chemically Pretreated Xanthosoma sagitifolium Roots

Abstract: Fresh samples of Xanthosoma sagitifolium were pretreated with sodium hexametaphosphate (SHMP), potassium metabisulphite (KMS), sodium chloride (NaCl) and aqueous ammonia, all in a concentration range of 1-5 % (w/v), and with glyceryl monostearate (GMS) at 0.025–0.125 % concentrations. The properties of these pretreated samples were compared with those of the control obtained by direct water extraction. The properties of the starch pretreated with chemicals showed characteristic changes regarding amylose contents, especially soluble amylose, and lipid extractability. Starch samples prepared from fresh roots pretreated with sodium chloride displayed a lower amylase digestibility. Control starch samples and the one prepared from roots pretreated with 5 % aqueous ammonia showed the highest amylase activity at 20 min incubation time. Other experimental samples showed only marginal changes.

Investigations of source-sink relations in cassava using reciprocal grafting.

Abstract: Source-sink relations in cassava were investigated following reciprocal grafting among three cultivars of different yield groups. Both rootstock and scion had significant effects on net assimilation rate and tuber yield, demonstrating that both sink capacity and source activity are important in achieving maximum tuber yield. The scion had no effect on tuber dry matter percentage and starch content of the grafts but the hydrocyanic acid content of the tuber was significantly influenced by both rootstock and scion.