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20072
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Subject: Crop Physiology × Author: KAU × Start date: 1984 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Crop-standard interactions in black pepper (Piper nigrum L.)
    (Department of plantation crops and spices, College of horticulture, Vellanikkara, 2007) Manjusha, C M; KAU; Sujatha, V S
    Black pepper, known as the King of Spices, is the most widely used spice in the world. Providing ideal support plays an important role in successful establishment of black pepper plantation. A study was carried out at the Department of Plantation Crops and Spices, College of Horticulture to unravel the interaction patterns of the Black pepper vines with different standards (supports) and to select the standard(s) ideal for trailing pepper. Black pepper var. Panniyur 1 trailed on 17 different standards (16 live + one dead) served as the experimental material. Characterisation of rhizosphere soil of pepper and root and shoot level interactions between pepper and standards were studied. Marked variations in the soil chemical and biological properties were noticed among the rhizosphere soil of different pepper-standard combinations. Significant variation was observed for pH, available Na, Mn, Cu and Zn in surface soil and available Na, Ca, Fe and Cu in subsurface soil. Available Mn and Cu had a significant negative influence on the dry yield of pepper. The rhizosphere region from which plants derive most of their nutrients are considered to be the seat of intense microbial activity. Variation in the microbial population of fungi, bacteria especially nitrogen fixing bacteria (NFB) and phosphate solubilising bacteria (PSB) and actinomycetes was significant in the rhizosphere soil of pepper trailed on different standards. Population of NFB and PSB was higher in the rhizosphere soil of pepper vines trailed on Artocarpus and Garuga and lower in Ailanthus and Erythrina. No significant variation was observed among various treatments with regard to dehydrogenase and phosphatase activities of rhizosphere soil. To assess the extent of root competition between black pepper and standards on which they are trailed, 32P soil injection technique was employed. Procedure involved applying 32P at the effective foraging space (EFS) of black pepper followed by quantification of radioactivity absorbed by pepper and standards. The standards viz. Ailanthus, arecanut, coconut and Grevillea had a complementary interaction with the pepper vine associated with them with respect to 32P uptake. Artocarpus, Azadirachta, Bombax and Pajanelia also exerted a similar effect but to a lesser extent. The other standards had a competitive influence on pepper based on the uptake pattern of 32P. For example, Erythrina had a more extensive root system than pepper and that pepper and Erythrina explore same extent of soil surface (Sankar et al., 1988). The effect of different standards on growth, yield and quality attributes of pepper was found to vary significantly in most of the characters studied. Coconut was superior to all other standards for growth characters of pepper like height of bearing column, number of laterals per 0.25 m2, number of berries per spike and spike compactness and expressed higher values for spread at chest height, number of spikes per 0.25 m2 and spike length. All these characters had a positive correlation with yield. Pepper gave high yield when trailed on coconut, Ailanthus and Artocarpus and medium yield when trailed on Acacia, Azadirachta, Bombax, Caesalpinia, Erythrina, Garuga, Grevillea, Gliricidia, Pajanelia, Thespesia and teak pole. Foliar nutrient content of pepper was influenced by the standards used but had no significant correlation with yield of pepper. But the foliar nutrient status of standards had significant correlation with yield of pepper. Phosphorus, iron and copper had recorded a negative effect and Mn, a positive effect on yield. Based on the present study, it could be concluded that the pepper production can be raised substantially by trailing it on suitable supports like coconut, jack and Ailanthus. For quick establishment of pepper gardens using standards propagated through stem cuttings, Garuga was found better compared to other standards propagated in a similar way.
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    ThesisItemOpen Access
    Genetic transformation of black pepper (piper nigrum L) for phytophthora foot rot resistance/tolerance
    (Department of plantation crops and spices, College of horticulture, Vellanikkara, 2007) Lissamma, Joseph; KAU; Valsala, P A
    Investigations on "Genetic transformation of black pepper (Piper nigrum L.) for Phytophthora foot rot resistance/tolerance" were carried out at the Department of Plantation Crops and Spices, and Centre for Plant Biotechnology and Molecular Biology, College of Horticulture, Vellanikkara during 2001-2006. Three selected black pepper varieties Panniyur 1, 4 and 6 were utilized for the study. Axenic cultures of the selected varieties were raised from nodal segments as well as ripe seeds for embryogenesis and transformation studies. Among the varieties average number of multiple shoot/explant was high for variety P­6 in ½ MS medium with BA and IAA 1.0 mg l-1. Somatic embryogenesis was induced on ripe seeds of the variety P6 at the micropylar region in ½ MS medium with inositol 1.0 g l-1. Further development of the somatic embryo observed in liquid shaking cultures of SH basal. Growth regulators like BA,2,4-D ,dicamba and thidiazuron did not give rise to embryogenesis in the different explants of black pepper. Multiple shoot induction from cotyledonary nodal explants and zygotic embryo explants were observed in all the varieties in ½ MS with 1.0 mg l-1 BA and IAA. Direct regeneration from leaf segments was also observed in the same media combination. Agrobacterium tumefaciens strains EHA105, AGL.1.1303, GV2260 and LBA4404 were used for the transformation work. Strain EHA105 contains the plasmid p35SGUSINT with gus A gene and npt II gene. The AGL.1.1303 contains the plasmid harbouring antibiotic resistant selectable marker genes (npt II and hpt IV) and GUS and GFP reporter genes. The GV2260 contain the plasmid pGV2260 with osmotin gene and npt II gene. The LBA4404 contains the plasmid pBZ100 containing alfalfa glucanase gene, rice chitinase gene and npt II gene. Sensitivity studies of black pepper tissues to various antibiotics resulted in selecting the optimum threshold level of antibiotic to be used in the screening medium. Kanamycin 25 mg l-1, 50 mg l-1, and 100 mg l- were selected as the cut off level for the selection of transformants from zygotic embryo, leaf segments and nodal segments respectively. Cefotaxime at 250 mg l-1 was selected for the effective elimination of Agrobacterium after infection. Genetic transformation was standardized with Agrobacterium strain EHA105 using leaf disc and zygotic embryo explants. Tentative protocol for transformation in black pepper include Agrobacterium inoculum density 0.9, infection time 10 min and co-cultivation period of 48 h. Acetosyringone at 50-100 µM favoured transformation. Transient gus assay revealed faint blue staining on the infected leaf explants. Explants, leaf segment, cotyledonary node and zygotic embryo were used for transformation with Agrobacterium strains AGL.1.1303, GV2260 and LBA4404. There was explant specificity for the different Agrobacterium strains used. With LBA4404 zygotic embryo explants gave maximum survival in the screening medium containing 50 mg l-1 kanamycin and 250 mg-1 cefotaxime. Direct gene transfer using gene gun attempted with pBZ100 and cotyledonary node explants. Bombarded explants were found surviving in the screening medium with kanamycin for four months. However molecular analysis of selected transformants through PCR revealed that npt II gene integration has not happened in the tissues subjected to PCR analysis.