In vitro Evaluation of Seed Germination in Twelve Alfalfa Cultivars under Salt Stress

Alfalfa(Medicago sativa L.),when exposed to abiotic stress such as salinity,suffers significant losses in yield and productivity.The present study evaluated the salinity tolerance of 12 alfalfa cultivars in vitro using five concentrations of sodium chloride(NaCl),ranging from 0 to 250 mmol L^(−1).The results obtained in the current study revealed that the Saudi cultivars,Kasimi and Hassawi,and the German cultivar(Berlin)had the highest salinity tolerance in terms of germination percentage(GP),corrected germination rate index(CGRI),days to reach 50%germination(GT_(50)),and ability to form cotyledonary and true leaves.Under mmol L^(−1) NaCl,the Saudi cultivar Kasimi cultivar showed GP,CGRI,and GT_(50) of 55.20%,123.15,and 3.77 days,respectively.Similarly,the German cultivar(Berlin)showed GP,CGRI,and GT_(50) of 50.06%,86.61,and 5.17 days,respectively.These findings might reveal a pivotal aspect in salt tolerance in alfalfa.Our results will help to select salt-tolerant alfalfa cultivars that could thrive in arid and semi-arid areas with salinity problems.

Physico-Chemical Properties of Compost Based Waste-Recycling of Grape Fruit as Nursery Growing Medium

The present study reports the physico-chemical properties of four compost based squeezed grape fruit wastes (SGFW) consisting of 60% SGFW + 40% chicken manure (including sawdust) (CMS) (v/v), 80% SGFW + 20% bean hay (BH) (v/v), 80% SGFW + 20% chicken manure (including wheat hay) (CMH) (v/v) and 100% SGFW. Results showed that 100% SGFW compost had a suitable pH and EC with 7.82 and 1.68 dSm-1, respectively. Also, 80% SGFW + 20% BH compost was very rich in organic matter similar to coco peat, but 80%SGFW + 20% CMH compost had the lowest C/N ratio (5.2). The N, P and K concentrations in SGFW composts were higher than the coco peat or vermiculite. The soluble cations (Ca2+, Mg2+, K+) and anions (CO23, HCO-3 ) in 60% SGFW+ 40% CMS compost were the highest among substrates. The concentrations of trace elements and heavy metals in SGFW composts were far lower than the range of phytotoxicity. On the other hand, total phenols in SGFW composts were higher than coco peat.