Influence of MH and carbendazim application in preventing loss of onion bulbs during storage was assessed in two varieties. Individual treatment of 2,000 ppm MH reduced the percentage of rotting, fungal infection and sprouting to a greater extent in variety 'N-53'. The preharvest treatment appeared more effective than the postharvest in this variety. In case of 'Local White' also a similar trend was observed but the response obtained in general was not promising. Preharvest treatment with carbendazim significantly reduced the rotting and fungal infection in both the varieties during storage. However a combined application of carbendazim and MH (1,000 ppm and 2,000 ppm, respectively) exhibited better results as compared to the individual treatments in both the varieties.
Authors:S. Figlan, T.A. Baloyi, T. Hlongoane, T.G. Terefe, H. Shimelis, and T.J. Tsilo
Phenotypic and genotypic evaluation of wheat genetic resources and development of segregating populations are pre-requisites for identifying rust resistance genes. The objectives of this study were to assess adult plant resistance (APR) of selected wheat genotypes to leaf rust and stem rust and to develop segregating populations for resistance breeding. Eight selected Kenyan cultivars with known resistance to stem rust, together with local checks were evaluated for leaf rust and stem rust resistance at seedling stage and also across several environments. Selected diagnostic markers were used to determine the presence of known genes. All eight cultivars were crossed with local checks using a bi-parental mating design. Seedling tests revealed that parents exhibited differential infection types against wheat rust races. Cultivars Paka and Popo consistently showed resistant infection types at seedling stage, while Gem, Romany, Pasa, Fahari, Kudu, Ngiri and Kariega varied for resistant and susceptible infection types depending on the pathogen race used. The control cultivars Morocco and McNair consistently showed susceptible infection types as expected. In the field, all cultivars except for Morocco showed moderate to high levels of resistance, indicating the presence of effective resistance genes. Using diagnostic markers, presence of Lr34 was confirmed in Gem, Fahari, Kudu, Ngiri and Kariega, while Sr2 was present in Gem, Romany, Paka and Kudu. Seedling resistance gene, Sr35, was only detected in cultivar Popo. Overall, the study developed 909 F6:8 recombinant inbred lines (RILs) as part of the nested mating design and are useful genetic resources for further studies and for mapping wheat rust resistance genes.
Authors:N. Aiter, A. Lehad, B. Haddad, A. Taibi, S. Meziani, Mohand-Larbi Rabhi, L. Khelifi, and C. Chaouia
Several grapevine viruses were reported in Algeria and especially in grapevine germplasm collection, therefore it is a great challenge to free these varieties from virus infection before any breeding programs. Our study focused on the development of chemotherapy on autochthonous varieties collected in the grapevine germplasm collection of ITAFV. All these varieties were tested by DAS-ELISA and the presence of GLRaV-3 and GFLV was confirmed in all used samples for the sanitation. After 8 weeks of shoot tips in vitro culture in a modified M S medium containing ribavirin, DAS-ELISA test revealed that GLRaV-3 was completely eliminated and GFLV to a significant rate.