Mohsin Bashir

Salicylic acid confers salt tolerance in potato plants by improving water relations, gaseous exchange, antioxidant activities and osmoregulation

BACKGROUND Potato is an important vegetable; however, salt stress drastically affects its growth and yield. A pot experiment was therefore conducted to assess salicylic acid efficacy in improving performance of potato cultivars, grown under salt stress (50 mmol L-1 ). Salicylic acid at 0.5 mmol L-1 was sprayed on to potato plants after 1 week of salinity application. RESULTS Salt stress effects were ameliorated by salicylic acid effectively in both the studied cultivars. N-Y LARA proved more responsive to salicylic acid application than 720-110 NARC, which confirmed genetic variation between cultivars. Salicylic acid scavenged reactive oxygen species by improving antioxidant enzyme activities (superoxide dismutase, catalase, peroxidases) and regulating osmotic adjustment (proline, phenolic contents), which led to enhanced water relation and gaseous exchange attributes, and thereby increased potassium availability and reduced sodium content in potato leaves. Moreover, potato tuber yield showed a positive correlation with potassium content, photosynthesis and antioxidant enzyme activities. CONCLUSION Salt tolerance efficacy of salicylic acid is authenticated in improving potato crop performance under salt stress. Salicylic acid effect was more pronounced in N-Y LARA, reflecting greater tolerance than 720-110 NARC, which was confirmed as a susceptible cultivar. Hence salicylic acid at 0.5 mmol L-1 and cultivation of N-Y LARA may be recommended in saline soil.

Clonal multiplication of guava (Psidium guajava) through soft wood cuttings using IBA under low-plastic tunnel

The present investigation on clonal multiplication of guava (Psidium guajava L.) soft wood cuttings was done with the aim to determine the most successful media and rooting hormone (IBA) concentration. Guava soft wood cuttings were treated with 0, 200, 400 and 600 mg kg -1 IBA solution when planted in three different rooting media (sand, silt and top soil) under low-plastic tunnel. The cuttings were allowed to grow under low-plastic tunnel for 90 day to evaluate the rooting capability and shooting competency. The study showed that the species has a great potential for clonal multiplication through soft wood cuttings. The highest number of roots and root length were observed in the cutting treated with 400 mg kg -1 IBA solution in sand, and the lowest in the cuttings without IBA treatment in sand media. In general 400 mg kg -1 IBA treatment with silt as rooting media performed better as compared to the other treatments. However, the highest survival percentage (50%) was observed in the cuttings rooted in silt media and treated with 200 mg kg -1 IBA solution. Experimental results showed the potential of clonal propagation of guava through soft wood cuttings treated with auxin under simpler and cheaper low-plastic tunnel.