Selection for salt tolrance in petunia grandiflora
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Date
2014
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Publisher
Central University of Punjab
Abstract
Petunia grandiflora a native of South America is a popular and high value ornamental plant in the world. Soil salinity is the major abiotic stress in semi-arid Malwa region of Punjab, adversely affecting its productivity, survival and quality. In order to develop salt resistant varieties of P. grandiflora, an attempt was made to select salt tolerant seedlings from varieties Violet Blue, Giant California and Nana compecta by using ex-vitro and in-vitro methods. Seedlings were subjected to salt treatments of 100 mM, 200 mM, 300 mM, 400 mM, 500 mM and 600 mM for durations of 4 hr, 6 hr, 12 hr and 24 hours. Salt treatment reduced shoot length, leaf number and survival percentages and delayed days to 50% flowering. Variety Nana Compecta was identified as tolerant to salt and variety Giant California was most sensitive to soil salinity. In in-vitro method of gradual increase in NaCl concentration (0, 25, 50, 75 and 150 mM) from low to high level was found to be a better approach for selecting salt tolerant calli as compared to direct method in which direct transfer of calli to high salt concentrations (50, 100, 150, 200, 250 and 300 mM) was found to be detrimental to callus survival and growth. Treatment of calli upto 50 mM salt concentrations was good for shoot regeneration in all the three varieties. Protocol was standardized for callus induction, direct shoot induction from leaves, shoot regeneration from callus and root induction from shoots. For callus induction, 2 mg/l 2, 4-D and 0.5 mg/l kinetin was optimum for variety Violet Blue and 1 mg/l both BAP and NAA was optimum for varieties Giant California and Nana Compecta. For direct shoot induction from leaves 2 mg/l BAP and 0.1 mg/l NAA were good for all the three varieties. For shoot regeneration from calli, 2 mg/l BAP in combination with 0.1 IAA for variety Violet Blue and 1 mg/l both BAP and NAA for varieties Giant California and Nana Compecta were ideal. For root induction, 0.5 mg/l NAA and 0.1 mg/l IBA were ideal for all the three varieties. Seeds from plants grown ex-vitro showing tolerance to salt were harvested and stored for further testing.
Description
Keywords
Petunia, Ornamental plant, Salinity stress, Callus induction, Shoot regeneration
Citation
Najar, Raoof Ahmad (2014) Selection for salt tolrance in petunia grandiflora.