Improved Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) for the rapid and sensitive detection of Yam mosaic virus

Yam (Dioscorea spp.) productivity is constrained significantly by the lack of a formal seed system. Vegetative propagation, through tuber setts as ‘seed’ yams, encourages the recycling of virus-infected planting materials, contributing to high virus incidence and yield losses. Efforts are ongoing to increase the production of high-quality seed yams in a formal seed system to reduce virus-induced yield losses and enhance the crop’s productivity and food security. Specific and sensitive diagnostic tests are imperative to prevent the multiplication of virus-infected materials contributing to a sustainable seed yam certification system. During routine indexing of yam accessions, discrepancies were observed between the results obtained from the reverse transcription loop-mediated isothermal amplification (RT-LAMP) test and those from reverse transcription polymerase chain reaction (RT-PCR); RT-LAMP failed to detect Yam mosaic virus (YMV) in some samples that tested positive by RT-PCR. This prompted the design of a new set of LAMP primers, YMV1-OPT primers. These primers detected as little as 0.1 fg/µL of purified RNA obtained from a YMV-infected plant, a sensitivity equivalent to that obtained with RT-PCR. RT-LAMP using YMV1-OPT primers is recommended for all future virus-indexing of seed yams for YMV, offering a rapid, sensitive, and cost-effective approach

Plant Cryopreservation Importance, Approaches and Future Trends

Plant cryopreservation is useful for long term storage of clonal germplasm and endangered species. Clonally propagated crops which produce recalcitrant seeds cannot be easily conserved using conventional methods. Preservation of plants in vitro is limited to two years and not ideal for germplasm storage for a very long time. The need to conserve plant genetic resources through cryopreservation techniques to mitigate the effects of climate change such as extinction of certain plant species cannot be underestimated. Different cryopreservation methods including dehydration, programmed freezing, vitrification and v cryo-plate are employed in the long-term storage of different plants. These methods are usually based on the principle of the removal of freezable water from tissues by physical or osmotic dehydration followed by ultra-rapid freezing. There have been several advancements in the identification and use of cryoprotective agents, nonetheless, its toxicity remains a challenge. To accelerate plant cryopreservation, there is the need for the development of global expertise. The current practice for the conservation of germplasm in the Biotechnology Laboratory in Ghana is through the use of slow growth media. Moving forward, there is the need to work on developing cryopreservation protocols for preservation of germplasm using liquid nitrogen and cryogenic refrigerators

Breeding Cassava for End-User Needs

A lot of research initiatives have gone into the breeding of cassava which has led to the development and release of over 30 cassava varieties in Ghana, of which adoption rate is 40%. This low adoption is due to inadequate promotion of improved varieties and the fact that some of the varieties do not meet end-user needs. With cassava becoming an important cash crop, it is important that breeding programmes refocus to define the market segments and objectives to facilitate the improvement of target traits such as poundability, dry matter content, starch and carotenoids that will lead to the development of varieties tailored towards end-user needs. This will in the long run promote food and nutritional security especially in low- and middle-income countries where the crop is a major staple. In addition, there should be more investment in high-throughput phenotyping to enhance the assessment and evaluation for the development of varieties with end-user traits. Subsequently, the cassava seed system should be formalized to enhance the production and dissemination of high-quality improved cassava varieties with end-user traits

Marker-Assisted Selection (MAS): A Fast-Track Tool in Tomato Breeding

Marker-assisted selection (MAS) is a complementary tool for conventional breeding where a molecular marker linked to a trait is indirectly selected. Many studies conducted have been able to identify and develop markers for traits such as disease and pest resistance and other abiotic stresses. Despite the availability of these markers, the technology has been extensively used in tomato breeding for the identification of some economic traits in particular disease resistance. In developed countries, MAS is utilized routinely in breeding programs, but this cannot be said for developing countries such as Africa. It is high time Africa as a continent looks at the importance of the technology and invests in it. In addition to MAS, other strategies such as marker-assisted backcrossing and recurrent selection have also been employed for breeding in tomato. The use of MAS in crop improvement will not only reduce the cost of developing new tomato varieties but will also increase the precision and efficiency of selection in the breeding program as well as lessen the number of years required to come up with a new crop variety

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Diversity Assessment of Some Sesame (Sesamum indicum L.) Genotypes Cultivated in Northern Ghana Using Morphological and Simple Sequence Repeat (SSR) Markers

In Ghana, sesame is cultivated in some districts of northern Ghana. Genotypes cultivated are land races that are low yielding leading to decline in production. There is the need for improvement of these land races to generate high yielding cultivars. Characterization of genetic diversity of the sesame land races will be of great value in assisting in parental lines selection for sesame breeding programmes in Ghana. Twenty-five sesame land races were collected from five districts in northern Ghana noted for sesame cultivation. Seeds collected were planted in three replicates in randomized complete block design and were evaluated for a number of morphological characters. Data collected were subjected to Principal Component Analysis (PCA) and a dendrogram showing similarity between the accessions were drawn. Data on number of capsules per plant, number of seeds per capsule, and plant height at flowering were subjected to analysis of variance using GenStat Discovery Edition 4. Molecular genetic diversity was assessed by using thirty eight SSR markers widely distributed across sesame genome to characterize the materials. Twenty-one out of the 38 primers were polymorphic. Cluster analyses using the Euclidean similarity test and a complete link clustering method were used to make a dendrogram out of the morphological data. Analysis of variance showed that capsule number was significantly different; a range of 54.9 and 146.7 was produced. The number of seeds per capsule varied significantly and the variation between highest and lowest accession in seed production was 33%. Plant height was also significantly different ranging from 60.6 to 94.1 cm. Using morphological traits the accessions clustered into two major groups and two minor groups and variation among accessions were 10-61%. On the other hand, SSR marker-based dendrogram revealed five major and two minor groups. It showed that variation among the accessions was low, 10-20%. Heterozygosity was 0.52, total alleles produced were 410, and average allele per locus was 19.52. Six accessions, C3, C4, S5, W1, W3, and W5 fell in five different clusters in the SSR dendrogram and in six clusters in the morphomolecular based dendrogram. These accessions were noted for high capsule number per plant and seeds number per capsule and are recommended for consideration as potential parental lines for breeding programme for high yield