Leaf Surface Scanning Electron Microscopy of 16 Mulberry Genotypes (Morus spp.) with Respect to their Feeding Value in Silkworm (Bombyx mori L.) Rearing

Abstract

Mulberry (Morus spp.) is the only silkworm (Bombyx mori L.) food plant. In Indian sub tropics, S-146 is the only popular and ruling mulberry genotype for silkworm rearing. As a result, mulberry leaf availability is always the limiting factor, and therefore, sub tropics are contributing less than 1% of the country’s total silk production compared with more than 60% under tropical conditions. Besides climatic conditions, this is due to a very limited number of mulberry genotypes available in this region for silkworm rearing. However, in the mean time, 15 mulberry genotypes viz. ‘Tr-10’, ‘Chinese White’, ‘K-2’, ‘Sujanpur Local’, ‘BC2 -59’, ‘S-1635’, ‘C-1730’, ‘Mandalaya’, ‘S-30’ (Vishala), ‘RFS-175’, ‘Anantha’, ‘C-2016’, ‘C-2017’, ‘S-41’ and ‘V-1’ were also introduced in the sub tropics, but remained unexplored. In sericulture, leaf surface is also an important parameter for, both, the silkworm’s acceptability of not having any feeding impediment and the mulberry improvement programs. The objective of this study was to explore the possibilities of using these 16 mulberry genotypes for their leaf surface characteristics by scanning electron microscopy and using them for sericulture. Based on leaf yield, stomatal size, stomatal number per unit of area and trichomes and idioblasts length, these genotypes were grouped into different categories. The mulberry genotype ‘Mandalaya’, in addition to the ruling genotype ‘S-146’ excelled because of their higher leaf yield and desired leaf surface characteristics. Furthermore, the genotypes ‘K-2’, ‘S-41’ and ‘Sujanpur Local’ are also suggested to develop high yield mulberry genotypes in the Indian sub tropics.