Wheat Seed Germination under Low Temperature and Moisture Stress¹

Abstract

Cultivate differ inherently in their response towards drought. Only those adapted to arid and semiarid conditions become established into uniform and vigorous stands during germination under moisture stress and suboptimal temperature. Seed germination of four wheat cultivars, ‘Najah’ and ‘Mexi‐pak’ (Triticum aestivum L.), and ‘Hurani’ and ‘Jori’ (Triticum durum L.), were compared under suboptimal temperatures and various levels of simulated moisture stress. Components of water uptake, germination percentage, speed of germination, root growth, respiration rate, and germination recovery from stress were measured. The rate of water uptake decreased and the time required for germination increased when the seeds were incubated at 6 atm and higher. Seeds of the four cultivars germinated when their moisture content was approximately 50% on a fresh weight basis. Total germination was not affected by moisture stress levels up to 12 atm but was significantly reduced at 15 and 18 atm osmotic tensions. Rate of root growth, speed of germination, and respiration rates were inversely related to moisture stress. Low moisture stress (3 atm) did not inhibit root growth. Significant differences were found among cultivars in the parameters studied. Perforating the pericarps did not eliminate the differences in water uptake and respiration rates between cultivars. Prolonged exposure of ungerminated seed to high osmotic tensions at low temperatures showed high seed germination recovery. These data suggest that any of the germination criteria used can be effective in selecting droughtresistant cultivars.

The Response of Sorghum, Groundnut, Sesame, and Cowpea to Seed Priming and Fertilizer Micro-Dosing in South Kordofan State, Sudan

“…Seed priming has been shown to reduce germination time, improve plant stand, increase vigor, shorten the growing cycle, and increase crop yield [5,7,8,15]. It is a technology that is particularly suited to adverse environmental conditions.…”

Effect of Hormonal Priming (GA3) and Osmopriming on Behavior of Seed Germination in Wheat (Triticum aestivum L.)

“…Seed germination was recorded daily up to day 7 after the start of the experiment. Germination percentage (GP) was calculated based on following equation: (Ashraf et al, 1978) GP Total germinated seed after 8days Total number of seed Then the mean germination rate was calculated according to the following equation: (Ellis et al, 1987) MGR= n / Dn www.ccsenet.org/jas Journal of Agricultural Science Vol. 4, No.…”

Effect of Priming on Seed Germination of Cucurbita Pepo under Copper Stress

“…A daily germination count (every 2 hours) was carried out for 9 days. The germination percentage (GP) is the proportion, expressed as percentage of germinated seeds to the total number of viable seeds that were tested by following formula [9]: GP = the number of seeds germinated/total number of seeds × 100 Tolerance index was calculated using following formulae [10]: Fresh weight of stress seedling/Fresh weight of control seedling × 100 The time to 50% germination (T50) was calculated according to the following formula of Coolbear et al [11] modified by Farooq et al [12]: T50 = t i + {(N/2) − n i } (t i − t j )/n i − n j Where N is the final number of germination and n i , n j cumulative number of seeds germinated by adjacent counts at times t i and t j when n i <N/2< n j .…”