Pathological Screening and SDS-PAGE Analysis of total Protein of Chilli Pepper Cultivars to Meloidogyne incognita

Chilli pepper (Capsicum annuum L.) is an economically important crop - relatively exclusive to Egypt- that shows moderate and high levels of susceptibility to several pests, including the pepper root-knot nematode, (RKN) Meloidogyne incognita. In this study, M. incognita succeeded in reproducing on all the pepper cultivars such as Balady Mecca, 292, Top Star, Dolma H54, and Lama Star. However, the Lama Star cultivar sustained the highest number of juveniles2 in soil, roots, and the total final number as well the rate of nematode build-up, 3.18 times (highly susceptible, HS). On the other four cultivars the nematode developed and reproduced relatively moderate susceptibility (MS) when compared with the others. With regard to plant health, Dolma H54 was the most susceptible cultivar, while Balady Mecca was the least affected one. Notably, shoot weight was reduced in cultivars infected with nematode when compared with the healthy ones. For instance, the percentages of shoot weight reduction ranged between 50.1 to 67.8 %, cv. Balady Mecca, recorded the lowest reduction while cv. Dolma H54 achieved the highest one. SDS-PAGE for the total storage protein of the current pepper cultivars (control and nematode-treated) has been performed. Current results suggest that nematode infection may trigger some gene expression (appears at molecular weight of about 60 kDa), causing the cultivars 'Balady Mecca', 'Dolma H54', '292' and 'Top Star' to exhibit MS to the nematode infection. While the protein pattern of the cultivar 'Lama Star' indicates that it might be HS for RKN infection.