ABSTRACT
Late Leaf Spot (LLS) disease is caused by Phaeoisariopsis personata, a devastating disease that significantly affects groundnut (Arachis hypogaea L.) production worldwide. This research aimed to investigate the disease progress in resistant and susceptible groundnut genotypes under green house conditions with artificial inoculations. The four popularly growing groundnut cultivars in Andhra Pradesh i.e., Kadiri-6 (K6), Dharani, Harithandra and Lepakshi (K-1812) were evaluated in this study. The disease severity scale, percent disease index (PDI), Area under disease progression curve (AUDPC) and the epidemic rate (rate) were estimated by using the linear model. Highest disease severity was observed in K6 (88.19 %) and Dharani (85.19 %) with greater disease progression rate was observed in K6 (0.13) and Dharani (0.12) cultivars. However, the lowest disease progression was observed in Lepakshi (0.04) and Harithandhra (0.08) cultivars. Enhanced resistance to LLS was reported with Harithandhra and Lepakshi cultivars due to slower epidemic rate, longer incubation and latent periods with smaller lesions.
ABSTRACT
The present investigation was undertaken to examine the genetic divergence in 50 mungbean germplasm lines for 13 characters using Mahalanobis D2 statistics. The genotypes grouped into eight clusters. Cluster VII had maximum intra-cluster distance while inter-cluster distance was highest between clusters V and VII. Cluster means indicated that none of the clusters was superior for all the characters studied. Therefore, hybridization between genotypes belonging to different clusters is suggested for development of superior genotypes. 10 SSR primers were used for molecular study of which only one gave slight difference among 19 mungbean genotypes. The quality and quantity of DNA used for amplification by PCR is the key to reproducible results and success of genotyping. Especially, DNA purity is extremely crucial for obtaining clear and discriminate patterns. DNA extraction from mungbean is difficult due to presence of contaminants such as phenols. Therefore, the present study was under taken to obtain high quality and pure DNA in mungbean. With few modifications four different DNA extraction protocols were tried in the present study to obtain high quality and pure DNA viz., (I) Doyle and Doyle (1987), (ii) Method of Murray and Thompson (1980), (iii) Porebski et al.(1997), and (iv) Lin et al. (2001). Out of the four methods tried for DNA extraction, the method of Lin et al. (2001) was found most efficient, as the DNA obtained through this protocol was relatively pure which gave amplyfying products in the PCR. The genotype used for the standardization was MGG -361. Molecular characterization of 19 randomly chosen mungbean genotypes was attempted with the eight standardized primers. None of the primers showed scorable polymorphism. The primers VR4, VR5 and VR9, exhibited non specific bands, in addition to the monomorphic bands.
ABSTRACT
Green gram is a widely cultivated pulse crop rich in protein, high in vitamin-B content and essential aminoacids. It is easily digestable and low flatulence produced crop. The quality and quantity of DNA used for amplification by PCR is the key to reproducible results and success of genotyping. Especially, DNA purity is extremely crucial for obtaining clear and discriminate patterns. DNA extraction from Green gram is difficult due to presence of contaminants such as phenols. Therefore, the present study was under taken to obtain high quality and pure DNA in Green gram. With few modifications four different DNA extraction protocols were tried in the present study to obtain high quality and pure DNA viz., (i) Doyle and Doyle (1987), (ii) Method of Murray and Thompson (1980), (iii) Porebski et al.(1997), and (iv) Lin et al. (2001). Out of the four methods tried for DNA extraction, the method of Lin et al. (2001) was found most efficient, as the DNA obtained through this protocol was relatively pure which gave amplifying products in the PCR. The genotype used for the standardization was MGG -361.