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  • ThesisItemOpen Access
    Vegetative propagation of promising jackfruit (Artocarpus heterophyllus Lam.) types
    (Department of Pomology and Floriculture, College of Agriculture,Padannakkad, 2018) Ashok Madala, KAU; Rajagopalan, A
    The investigation on ‘Vegetative propagation of promising jackfruit (Artocarpus heterophyllus Lam.) types’ was conducted at the College of Agriculture, Padannakkad, Kasaragod during the period 2017 - 18 to evaluate the success of epicotyl and softwood grafting in promising types of jackfruit and to examine the variation among jackfruit types with respect to grafting methods. The experiment comprised of five promising types of jackfruits viz., V1 - Varikka - early bearing (KJ 186), V2 - Gumless (KJ 397), V3 - Seedless (KJ 180), V4 - Cluster (KJ 182) and V5 - Muttam varikka (KJ 231) and two method of grafting i.e., M1 - epicotyl grafting and M2 - softwood grafting. The experiment was laid out in factorial CRD with three replications. The different jackfruit types showed significant influence for all the parameters studied except number of branches. Type V2 resulted in earliest sprouting (26.50 days) and maximum sprouting percentage of grafts (41.91 per cent) while type V3 recorded maximum survival percentage (66.94 per cent) and shoot length (8.13 cm). Maximum shoot girth (1.50 cm), number of nodes (7.50), number of leaves (7), length of leaf (12.34 cm) and breadth of leaf (5.64 cm) were observed in type V4. On the other hand, the maximum days to sprouting (30.33 days), minimum sprouting percentage (28.77 per cent), minimum shoot length (6.43 cm) and minimum number of leaves (5.17) were recorded in type V5 while type V1 showed minimum survival percentage (38.89 per cent), shoot girth (1.15 cm), leaf length (8.41 cm) and breadth of leaf (4.22 cm). Among the methods of grafting, the results on percentage of sprouting and survival as well as number of branches were not significant while all other parameters showed significant effects. Epicotyl grafts resulted in early sprouting of buds (26.00 days) and maximum shoot length (7.36 cm) whereas maximum shoot girth (1.36 cm), number of nodes (6.13), number of leaves (6.33), length of leaf (11.16 cm) and breadth of leaf (5.29 cm) were observed in softwood grafts. The interaction of varieties and methods of grafting were significant in most of the characters recorded. Interaction V2 x M1 was found better in early sprouting (24.33 days) and V2 x M2 resulted in maximum sprouting percentage (46.90 per cent) while V3 x M1 gave maximum survival of grafts (86.67 per cent). Hence, for the mass multiplication of Seedless type epicotyl grafting could be adopted and for other types like early bearing varikka, Gumless and cluster, softwood grafting could be practiced.
  • ThesisItemOpen Access
    Effect of heat stress on the expression patterns of different growth related genes in Malabari goats
    (Academy of Climate Change Education and Research, Vellanikkara, 2018) Angel Sunny, P; KAU; Bagath, M
    The impact of heat stress on growth performance of goats has been established fairly based on changes associated with phenotypic traits. However, not many reports are available on the genotypic traits which get altered on exposure to heat stress in livestock. Therefore, the study is an attempt to elucidate the molecular mechanisms governing growth performance during heat stress in goats. The primary objective of the study was to establish the influence of heat stress on the expression patterns of different growth related genes in Malabari goats. The study was conducted for a period of 45 days in twelve Malabari goats randomly allocated into two groups: MC (n=6; Malabari control) and MHS (n=6; Malabari Heat stress). Goats were stall-fed with a diet composed of 60% roughage and 40% concentrate. All animals had access to adlibitum feed and water and they were fed and watered individually. The MC goats were placed in the shaded pens while MHS goats were exposed to heat stress in outside environment between 10.00 h to 16.00 h. At the end of study period, all 12 animals were slaughtered and their liver tissues were collected for gene expression and histopathological studies. The temperature-humidity-index (THI) inside the shed (74.9) proved that the animals were not stressed while in the outside environment (86.5) the animals were extremely distressed. The hepatic growth hormone (GH), growth hormone receptor (GHR), insulin-like growth factor-1 (IGF-1), leptin (LEP) and leptin receptor (LEPR) gene expression patterns were significantly (P<0.05) lower in heat stress group as compared to the control group animals. In addition, negative correlation (P<0.05) was also established between THI and all the growth related gene expression in the study. The hepatic histopathological section showed more fatty and degenerative changes (P<0.05) in hepatocytes in MHS group as compared to MC group. The study offers the first thorough insight into the expression patterns of different growth related genes during heat stress exposure in goats. Further, the study established GH, GHR, IGF-1, LEP, LEPR genes to be the ideal markers to reflect growth potential in Malabari goats. The findings from this study provide some crucial initial information on how different growth relatedgenes are expressed when Malabari goats are subjected to heat stress. This information might be of high value in assessing the growth performance of goats and may provide useful information pertaining to nutrient supplementation to the heat stressed goats.