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Author: Anjana, Chandran × Author: KAU × End date: 2012 × Start date: 2012 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Evolving superior types in thippali (piper longum L) utilising bisexual variants
    (Department of Olericulture, College of Horticulture, Vellanikkara, 2012) Anjana, Chandran; KAU; Sujatha, V S
    The study on “Evolving superior types in thippali (Piper longum L.) utilising bisexual variants” was carried out at the Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara during the period 2010 to 2012. The objective of the programme was production of Piper longum hybrids and back crosses and their evaluation for growth, yield and quality. The investigations consisted of three experiments viz., developing hybrids and back crosses, evaluation of hybrids in pots and preliminary evaluation of selected female and bisexual types in the field. To induce bisexual flowers using growth regulators, NAA 50 mg l-1, NAA 100 mg l-1 and BA 500 mg l-1 were applied. Vegetative growth and spike production were adversely affected by both concentrations of NAA and there was no inflorescence production in NAA treated plants. In BA 500 mg l-1 treated plants, there was a marginal increase in bisexual flowers. Utilising bisexual type as one of the parents, spike set and seed set could be obtained only in crosses involving bisexual types as male parent and pure female type as female parent. Maximum per cent of spike set was obtained during October followed by November and maximum seed set during July followed by September when bisexual type I was used as male parent. When bisexual type II was used as male parent, per cent spike set was maximum during December followed by October. However, seeds obtained were maximum during September followed by October. Back crossing was attempted using predominantly bisexual hybrids either as male parent or as female parent. Even though spike set was obtained, when predominantly bisexual hybrids were used as male parent and pure female as female parent, no seed set could be obtained. Detailed observations on vegetative characters were recorded in the hybrids produced under earlier projects (Kanimozhi, 2010; Sujatha, 2011). Leaf lamina was codrate, ovate-elliptic or elliptic-lanceolate. Variation was also observed for shape of leaf base like cordate or oblique. Margins of leaves were either wavy or entire. Venation was acrodromous in all hybrids, which is typical of Piper longum. Colour of immature leaves varied from light green to green and mature leaves from green to dark green. Hybrids showed high amount of variability for reproductive characters like sex form, spike shape, size, colour and per cent of flowers of different sex forms in a spike. Shape of spikes varied from filiform, cylindrical or globular. Colour of immature spikes were green, light green or yellow. Mature spike colour also ranged from light green, green, and dark green or yellow. During the present study, 169 seeds were produced, of which 32 seeds germinated. Observations on germination and early growth characteristics of seedlings were taken. Number of days taken for germination of seeds varied from 33 to 71 days. Number of days taken from germination to opening of cotyledonary leaf varied from 4 to 21. The first true leaf appeared in 10 to 33 days. Ten hybrids, either female or bisexual were selected for preliminary evaluation in the field. Two check varieties, pure female type and the variety Viswam were also planted. The design adopted was CRD with four replications. Even though, the key morphological characters were same for all the accessions, which were typical for Piper longum, high amount of variability was observed for quantitative characters like number of main branches, length of longest stem, length and width of leaves, length of petiole, number of spike bearing branches per stem, spike and pedicel length, fresh and dry weight of spike, yield and driage. Per plant yield was highest for Viswam followed by Acc. no. 9. Spike characters of Acc. no. 9 were comparable to Viswam. Oleoresin content of Acc. no. 9 was superior to Viswam but oil and piperine contents were lower. Pests and diseases scoring were also done. The main disease noticed was leaf spot caused by Colletotrichum gloeosporioides and pests were not severe. Further detailed studies involving more promising hybrids are required to evolve superior varieties with high yield and quality.