Plant regeneration from leaf explants of mulberry: influence of sugar, genotype and 6-benzyladenine.

A protocol for plant regeneration from leaf explants was developed for tropical mulberry varieties. Effect of sugars, 6-benzyladenine and genotype on shoot regeneration was studied. Highest percentage of shoot regeneration (80 +/- 6) was obtained with genotype S799 on medium containing glucose and 8.9 microM 6-benzyladenine. Genotypes Mandalaya and MIHP, having thicker leaves with waxy cuticle, showed poorer regeneration ability than S799 and Sujanpur-5, which have thinner leaves and cuticle. Histological studies revealed that shoots regenerated from sub-epidermal cells.

Stress responses in two genotypes of mulberry (Morus alba L.) under NaCl salinity.

Changes in biomass yield rates, cell membrane stability (CMS), malondialdehyde (MDA) content and in the levels of physiological stress markers such as proline and glycine betaine in two high yielding genotypes (S1 and ATP, salt tolerant and salt sensitive, respectively) of mulberry under NaCl salinity were studied. Biomass yield rates and CMS were significantly decreased in both the genotypes under stress conditions. Per cent of decrease in biomass yield rate and CMS was relatively less in S1 than in ATP. Salt stress results a significant increase in the accumulation of proline, by 6-fold in S1 and 4-fold in ATP. Glycine betaine content was also increased significantly in stressed plants. However, the per cent increase was more in S1 than in ATP. The level of lipid peroxidation as indicated by MDA formation was greater in ATP than in S1. These results clearly support the better salt tolerant nature of S1 compared to ATP genotype.