Titles (4)Keywords (1)Abstracts (2)
Detection of molecular markers linked to Ry genes in potato germplasm for marker-assisted selection for extreme resistance to PVY in AAFC's potato breeding program, Nie, X., Lalany, F., Dickison, V., Wilson, D., Singh, M., De Koeyer, D. and Murphy, A., in: Canadian Journal of Plant Science, volume 96, number 5, pages 737-742, ISSN 0008-4220, 2016. [DOI]
 
Development of molecular marker for pro vitamin A carotenoid (pVAC) genes in cassava, Gedil, M. and Enok, L., Abstract in Book of Abstracts of the 11th Triennial Symposium of ISTRC-AB, held at Memling Hotel, Kinshasa. 4-8 October, 2010.
 
Simple sequence repeat markers and endogenous phytochemicals associated with somatic embryogenesis in Dioscorea alata L. and Dioscorea rotundata poir, Ossai, C. O.*, University of Ibadan, 2021.
 
Validation of striga hermonthica resistance markers and screening for candidate genes for striga resistance in selected Zea mays population, Najjuma, E.*, University of Ibadan, 2021.
 
Agrobacterium-mediated genetic transformation of yam (Dioscorea rotundata): an important tool for functional study of genes and crop improvement, Nyaboga, E., Tripathi, J., Manoharan, R. and Tripathi, L., in: Frontiers in Plant Science, volume 5, number 463, pages 1-14, ISSN 1664-462X, 2014. [DOI]
 
Keywords:Dioscorea rotundata; Marker genes; Reporter genes; Agrobacterium tumefaciens; Genetic transformation

Identifying aflatoxin resistance-related proteins/genes through proteomics and RNAi gene silencing, Chen, Z. Y., Brown, R., Guo, B. Z., Menkir, A. and Cleveland, T. E., in: Peanut Science, volume 36, number 1, pages 35-41, ISSN 0095-3679, 2009.
 
Abstract:
Aflatoxins are carcinogenic secondary metabolites produced mainly by Aspergillus flavus Link ex. Fries, and A. prarasiticus Speare during infection of susceptible crops, such as maize, cottonseed, peanuts and tree nuts. This paper will review research efforts in identifying aflatoxin resistance-related proteins/genes in maize. Similar strategies may be useful in peanut. For maize, although genotypes resistant to A. flavus infection or aflatoxin production have been identified, the incorporation of resistance into commercial lines has been slow due to the lack of selectable markers and poor understanding of host resistance mechanisms. Recently, resistance-associated proteins (RAPs) were identified through proteomic comparison of constitutive protein profiles between resistant and susceptible maize genotypes. These proteins belong to three major groups based on their peptide sequence homologies: storage proteins, stress-related proteins, and antifungal proteins. Preliminary characterization of some of these RAPs suggest that they play a direct role in host resistance, such as pathogenesis-related protein 10 (PR10), or an indirect role, such as glyoxalase I (GLX I), through enhancing the host stress tolerance. To verify whether these RAPs play a role in host resistance, RNA interference (RNAi) gene silencing technique was used to silence the expression of these genes in maize. RNAi vectors (glx I RNAi and pr10 RNAi) were constructed using Gateway technology, and then transformed into immature maize embryos using both bombardment and Agrobacterium infection. The extent of gene silencing in transgenic callus tissues ranged from 20% to over 99%. The RNAi silenced transgenic maize seeds have also been obtained from plants regenerated from Agrobacterium transformed callus lines. Kernel screen assay of the transgenic maize kernels demonstrated a significant increase in susceptibility to A. flavus colonization and aflatoxin production in some of the silenced transgenic lines compared with non-silenced control kernels, suggesting the direct involvement of these two proteins in aflatoxin resistance in maize.

Utilization of ESTs from cassava (Manihot esculenta Crantz): progress on development of EST-SSR markers and an oligo DNA microarray, Ingelbrecht, I., Jorgensen, K., Bak, S., Gorodkin, J., Raji, A., Winter, S., Lokko, Y., Gedil, M., Anderson, J., Moller, B. and Dixon, A., 2008.
 
Abstract:
Cassava is one of the most important sources of carbohydrates for over 500 million people in the tropics and subtropics. Cassava can be cultivated under conditions considered marginal for most other staple crops and has the added advantage of being utilized as an industrial crop for producing starch and derived products. Thus, cassava appeals to resource-limited, small-scale farmers as well as commercial farming systems. Due to high levels of heterozygosity and low flowering, breeding of cassava is arduous and advances in biotechnology could complement conventional breeding programs. However, as an orphan crop, tools for biotechnology-mediated improvement of cassava are currently limited. To enhance available genomics resources for cassava, we generated and characterized an 18,166 Expressed Sequence Tag (EST) dataset enriched for drought responsive genes. This dataset contains 8,577 unigenes comprised of 3,194 clusters and 5,383 singletons. About 63% of these ESTs could be annotated, while 11% were homologous to hypothetical genes with unknown function. The remaining 26% were not significantly homologous to sequences in public databases. To increase the repertoire of markers for molecular genetic applications, we identified Simple Sequence Repeats (SSRs) from this EST resource and validated these using a diverse cassava panel. We also utilized this EST resource, as well as publicly available sequences, to develop a 60-mer oligo DNA microarray: a total of 35,785 ESTs were assembled into 5,230 contigs and 8,838 singletons and used to design an array with ~11,000 probes for transcriptome analysis. Progress in these areas will be presented.