Of these 25 isolates, three were new (RR2A, RR15, RR83) from cultivars Co 7717, Co J83 and Co S88230, respectively, pathologically characterized on 13 standard differential PI3K Inhibitor Library supplier hosts. Isolates Cf 01, Cf 08 and RR15 were the most, and Cf-07 the least virulent. Molecular characterization using random amplified polymorphic DNA, universal rice primers (URP) and inter simple sequence repeat markers amplified a total of 161 alleles of which 159
were polymorphic (98.76%). Unweighted paired group method with arithmetic averages analysis of combined data of all the DNA markers obtained by three marker systems classified 25 isolates into six clusters at 34% genetic similarity with high Mantel matrix correlation (r = 0.83). The principal DMXAA component analysis (PCA) of marker data explained 68% of the variation by first three components. Molecular diversity as revealed in these isolates is very high, but non-structured. Isolate Co Pant 84212 was found to be genetically most diverse. We demonstrated for the first time that URPs derived from weed rice could successfully assess genetic diversity in C. falcatum. Molecular characterization of the C. falcatum isolates prevalent in north-eastern India would enable red rot management strate-gies, selection for resistance genes and development of resistant cultivars. “
“Severe growth abnormalities, including
leaf yellowing, sprout proliferation and flower virescence and phyllody, were found on Brassica rapa subsp. pekinensis plants in Poland. The presence of phytoplasma in naturally infected plants was demonstrated by polymerase chain reaction assay employing phytoplasma click here universal P1/P7 followed by R16F2n/R16R2 primer pairs. The detected phytoplasma was identified using restriction fragment length polymorphism analysis (RFLP) of the 16S
rRNA gene fragment with AluI, HhaI, MseI and RsaI endonucleases. After enzymatic digestion, all tested samples showed restriction pattern similar to that of ‘Candidatus phytoplasma asteris’. Nested PCR-amplified products, obtained with primers R16F2n/R16R2, were sequenced. Sequences of the 16S rDNA gene fragment of analysed phytoplasma isolates were nearly identical. They revealed high nucleotide sequence identity (>98%) with corresponding sequences of other phytoplasma isolates from subgroup 16SrI-B, and they were classified as members of ‘Candidatus phytoplasma asteris’. This is the first report of the natural occurrence of phytoplasma-associated disease in plants of Chinese cabbage. “
“Black leaf mould (BLM), caused by Pseudocercospora fuligena, is a major fungal foliar disease of greenhouse-grown tomatoes in the humid tropics. Quantifying the disease and yield loss from seasonal plantings will help mitigate the heavy reliance on frequent sprays of curative fungicides.