Abstract Detail

Ecophysiology

Gul , Bilquees  [1], Bano, Sonia [1], Ahmed, M. Z [2], KHAN , M AJMAL [3].

Humic acid application alleviated dark and salinity enforced dormancy in halophyte seeds.

Humic acids are widely reported to improve stress tolerance of crop plants at both seed germination and growth stages. However, little information is available on their roles in improving seed germination and growth of halophytes under different stress conditions. This study was therefore designed to determine whether exogenous application of humic acid (250 and 500 mg L^-1) could improve seed germination and seedling growth of some local halophytes (Poaceae: Halopyrum mucronatum, Desmostachya bipinnata, Urochondra setulosa, Phragmites karka, Aeluropus lagopoides; Cyperaceae: Cyperus conglomeratus; Amaranthaceae: Arthrocnemum macrostachyum, Halopeplis perfoliata, Halocnemum strobilaceum; Brassicaceae: Lactuca sativa, Lepidium latifolium) under saline conditions, sub-optimal temperature regimes and in dark. Humic acid applications had no significant effect on rate and final seed germination of all test species under saline conditions, except in U. setulosa seeds where ~50% improvement was observed under saline conditions. Some improvement (P < 0.001) in seedling length of Halopyrum mucronatum, Desmostachya bipinnata, Phragmites karka, Lactuca sativa and Lepidium latifolium  was also seen under non-saline conditions due to humic acid treatments especially with high dose (500 mg L^-1). Partial (15%) improvement in seed germination at 10/20^oC (suboptimal temperature) due to humic acid occurred in A. lagopoides but not in other species.  However, humic acid applications had pronounced effect in alleviating the dark-enforced dormancy of positively photoblastic seeds, particularly under saline conditions. These results indicate greater role of humic acid in reducing light but not temperature requirements and salinity tolerance of halophyte seeds.

1 - University of Karachi, Institute of Sustainable Halophyte Utilization, Karachi, 75270, PAK
2 - University of Karachi, Institute of Sustainable Halophyte Utilization, Karachi, 75270, Pakistan
3 - Qatar University, Centre for Sustainable Development, Doha, Dawha, ., Qatar

Keywords:
halophyte
light
salinity
Seed germination
temperature.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PEP003
Abstract ID:185
Candidate for Awards:None