Abstract
Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important grain legumes worldwide and its production is affected by increasing soil salinity due to global climate change. An experiment was conducted at the Plant Physiology Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh to evaluate the germination capability of seven cowpea genotypes under salt stress. The germination test was carried out in Petri dishes following two factorial CRD with three replications. Seven cowpea genotypes viz, Red Pine, Green Super, Hai Jiang San Hao, Kegornatki, Kegornatki Green, Kegornatki HYV & Kegornatki Red; and three salt levels viz, 0, 6 & 12 dSm-1, were used as experimental treatments. The germination percentage (GP), mean germination time (MGT), radicle and plumule length, radicle and plumule fresh and dry weight and different stress tolerance indices were recorded to screen the genotypes for salt tolerance. The study highlighted that salt concentrations drastically reduced seed germination and significantly delayed the process in all genotypes. The GP, length and biomass of radicle and plumule and salt tolerance indices were significantly decreased while the MGT was significantly increased with increasing salt stress in all cowpea genotypes. A significant variation among the genotypes in response to salt stress was also observed. Among the seven cowpea genotypes, Hai Jiang San Hao and Green Super showed higher salt tolerance in comparison to the other genotypes based on the measured traits; these genotypes can be used for further breeding program and/or cultivation in coastal saline prone areas with further investigation.
 J. Bangladesh Agril. Univ. 17(1): 39–44, March 2019
Highlights
Soil salinity is a serious threat to crop production, biodiversity, food and nutritional security
The highest germination percentage (GP) was recorded in Green Super and Hai Jiang San Hao and the lowest was found in Red Pine and Kegornatki Green in control condition
The lower mean germination time (MGT) was found in Hai Jiang San Hao followed by Kegornatki Red and higher was observed in Red Pine at 6 dSm–1 salt treatment (Fig. 3)
Summary
Soil salinity is a serious threat to crop production, biodiversity, food and nutritional security. Intrusion of saline water into cultivable lands due to sea level rise as a consequence of global warming exacerbates soil salinity in the coastal areas of Bangladesh. Salinity affected area in Bangladesh has increased from 8,330 square km in 1973 to 10,560 square km in 2009 (SRDI, 2010). Salinity is a great constraint to growing crops, especially in rabi season (dry months) when soil salinity arises and reaches to the peak in March-April before monsoon starts (Haque et al, 2008). Most crop plants are susceptible to saline soil and cowpea (Vigna unguiculata (L.) Walp.) is considered as highly susceptible to salt stress (McKenzie, 1988). Cowpea is an important seed legume crop in Bangladesh. Salinity stress reduced the speed and percentage germination of seed, decreased in shoot length, fresh and dry weights of shoots and roots of plants (Fateme et al, 2010). Salt stress can lead to oxidative stress due to increased production of reactive oxygen species (ROS), such as singlet oxygen (1O2), superoxide anion (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (Bray et al, 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
