Twenty five cultivars were screened for germination
at low (10°C), moderate (30°C) and at stress (40°C) temperatures.
Three cultivars were chosen such as Texas Cream 40 was able to germinate
at very high and low temperatures. Black Crowder demonstrated acceptable
germination at high temperatures but negatively affected at low temperature.
The main sugars present in cowpea seed were sucrose, raffinose and stachyose.
Sugar contents were affected by cultivar, type of tissue and temperature.
Sucrose contents were higher in embryo tissue of cultivars with low percent
germination and reduced in the cultivar with higher percent germination
suggesting the use of sucrose for germination. Sucrose decreased greatly
at 30°C and increased again at 40°C. Raffinose and stachyose contents
were higher in ungerminated seed. In germinated seed, raffinose and stachyose
contents were found only in cotyledon tissues at 10°C. Peroxidase
activities was affected by cultivars, type of tissue and temperature.
The highest peroxidase activity was found at low temperature (10°C)
in embryo tissue of the cultivar with the highest germination. High peroxidase
activity was related to ability of seed to germinate at low temperature.
Shahidul Islam, R. Carvajal R. Carmen and Jr. James O. Garner, 2009. Carbohydrate Compositions and Peroxidase Activity in Ungerminated,
Cotyledon and Embryo Tissues of Vigna unguiculata L. Walp Seed
Grown Under Stress Temperatures. American Journal of Plant Physiology, 4: 9-17.