A simple and cost effective liquid culture system for the micropropagation of two commercially important apple rootstocks.

The two commercially important apple rootstocks i.e., MM106 and B9 were micropropagated using a liquid culture system. Three different strengths of 0.8% agar solidified PGR free basal MS medium were first tested to optimize the culture media for both the rootstocks. Full strength medium (MS0) supported maximum in vitro growth, multiplication, rooting and survival under field conditions as opposed to quarter and half strength media. When three different volumes of liquid MS0 were tested, highest in vitro growth, multiplication, rooting and also survival under field conditions were achieved in 20 mL liquid MS0. The cost of one litre of liquid medium was also reduced by 8 times to Rs. 6.29 as compared to solid medium. The cost of 20 mL medium was further reduced to Rs. 0.125.

Coat protein sequence shows that Cucumber mosaic virus isolate from geraniums (Pelargonium spp.) belongs to subgroup II.

A viral disease was identified on geraniums (Pelargonium spp.) grown in a greenhouse at the Institute of Himalayan Bioresource Technology (IHBT), Palampur, exhibiting mild mottling and stunting. The causal virus (Cucumber mosaic virus, CMV) was identified and characterized on the basis of host range, aphid transmission, enzyme linked immunosorbent assay (ELISA), DNA-RNA hybridization and reverse transcription polymerase chain reaction (RT-PCR). A complete coat protein (CP) gene was amplified using degenerate primers and sequenced. The CP gene showed nucleotide and amino acid homology up to 97%-98% and 96%-99%, respectively with the sequences of CMV subgroup II. The CP gene also showed homologies of 75%-97% in nucleotide and 77%-96% in amino acid with the CMV Indian isolates infecting various crops. On the basis of sequence homology, it was concluded that CMV-infecting geraniums in India belong to subgroup II.