Tariq Mahmud Shah

Field Evaluation of Mungbean Recombinant Inbred Lines against Mungbean Yellow Mosaic Disease Using New Disease Scale in Thailand

Studies were conducted to identify the sources of resistance in mungbean recombinant inbred lines (RILs) in Thailand against mungbean yellow mosaic disease (MYMD). 146 mungbean RILs in series were evaluated in a field including resistant parent NM-10-12-1 and susceptible parent KPS 2 during summer 2008 under high inoculum pressure. The RILs were subsequently scored for disease symptom severity ratings (DSSR) using a new scale. Observations regarding DSSR and % disease index (%DI) showed that the tested RILs responded differently to the disease. A large number of RILs (132) were found highly susceptible, 12 were susceptible, 3 were tolerant and one was resistant. Overall screening results showed that three RILs, viz. line no. 30, 100 and 101 had minimum DSSR and % disease index thus they are good source of resistance to MYMD in spite of high disease pressure and can therefore be used directly as varieties to manage the disease in Thailand.

Detection of quantitative trait loci for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean (Vigna radiata (L.) Wilczek) in India and Pakistan

Yellow mosaic disease (YMD) is one of the major diseases affecting mungbean (Vigna radiata (L.) Wilczek). In this study, we report the mapping of the quantitative trait locus (QTL) for mungbean yellow mosaic India virus (MYMIV) resistance in mungbean. An F8 recombinant inbred line (RIL) mapping population was generated in Thailand from a cross between NM10-12-1 (MYMIV resistance) and KPS2 (MYMIV susceptible). One hundred and twenty-two RILs and their parents were evaluated for MYMIV resistance in infested fields in India and Pakistan. A genetic linkage map was developed for the RIL population using simple sequence repeat (SSR) markers. Composite interval mapping identified five QTLs for MYMIV resistance: three QTLs for India (qYMIV1, qYMIV2 and qYMIV3) and two QTLs for Pakistan (qYMIV4 and qYMIV5). qYMIV1, qYMIV2, qYMIV3, qYMIV4 and qYMIV5 explained 9.33%, 10.61%, 12.55%, 21.93% and 6.24% of variation in disease responses, respectively. qYMIV1 and qYMIV4 appeared to be the same locus and were common to a major QTL for MYMIV resistance in India identified previously using a different resistant mungbean.

Biochemical alterations in the leaves of different Desi and Kabuli type chickpea genotypes infected by phytoplasma

Abstract Objective: Chickpea phyllody caused by phytoplasma occurs worldwide. However, the alterations in the host physiology and its associated biochemical components induced by the infection with phytoplasma in chickpea plant remain unknown. Methods: In present study, the changes in phenolic compounds, protein contents, phenylalanine ammonia-lyase (PAL), peroxidase (POX), catalase (CAT), polyphenol oxidase (PPO) and chlorophyll contents were analyzed in phytoplasma-symptomatic and non-symptomatic plants of two Kabuli and three Desi type chickpea genotypes. Results: Total phenols were statistically at par in symptomatic plants of both Kabuli and one Desi (Bittle-98) genotype but significantly increased in genotype Aug-424 and decreased in C-727. Protein contents were significantly decreased in symptomatic plants of all genotypes except CM-2008. PAL activity was significantly increased in all Kabuli but decreased in all the Desi genotypes. POX activity was significantly increased in Noor-2009 and Aug-424 but decreased in CM-2008 and Bittle-98. PPO activity was increased in two genotypes but decreased in others. CAT activity and chlorophyll contents were decreased in all genotypes. Conclusion: The present finding indicates that phytoplasma causes non-specific, general stress response by interfering with host metabolism and photosynthesis. The study also provided significant insights for better understanding the mechanisms of chickpea plant response to phytoplasma. Özet Amaç: Fitoplazmın neden olduğu nohut bitkisinde oluşan phyllodi dünya genelinde görülmektedir. Ancak, nohut bitkisinde fitoplazma enfeksiyonu ile indüklenen konukçu fizyolojisinde ve buna bağlı biyokimyasal bileşenlerdeki değişiklikler bilinmemektedir. Yöntemler: Bu çalışmada, fenolik bileşikler, protein içerikleri, Fenilalanin amonyak-liaz (PAL), peroksidaz (POX), katalaz (CAT), polifenol oksidaz (PPO) ve klorofil içeriklerindeki değişiklikler fitoplazma-semptomatik ve semptomatik olmayan iki Kabuli ve üç Desi türü nohut genotipinde çalışıldı. Bulgular: Toplam fenoller, hem Kabuli hem de bir Desi (Bittle-98) genotipinin semptomatik bitkilerinde eşit düzeyde bulunurken„ Aug-424 genotipinde anlamlı olarak artmış, C-727′de ise azalmıştır. CM-2008 dışındaki tüm genotiplerin semptomatik bitkilerinde protein içeriği önemli ölçüde azalmıştır. PAL aktivitesi tüm Kabuli genotiplerinde önemli ölçüde artmış, ancak tüm Desi genotiplerinde azalmıştır. Noor-2009 ve Aug-424′de POX aktivitesi önemli ölçüde artmış ancak CM-2008 ve Bittle-98′de azalmıştır. PPO aktivitesi iki genotipde artmış ancak diğerlerinde azalmıştır. Tüm genotiplerde CAT aktivitesi ve klorofil içeriği azalmıştır. Sonuç: Bu bulgular, fitoplasmanın konukçu metabolizmasına ve fotosenteze müdahale ederek spesifik olmayan, genel stres tepkisine neden olduğunu göstermektedir. Çalışma ayrıca, nohut bitkisinin fitoplasmaya tepki mekanizmalarını daha iyi anlamak için önemli bilgiler sağlamıştır.