Chromogenic detection of yam mosaic virus by closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP)

A closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP) assay was developed for the detection of yam mosaic virus (YMV, genus Potyvirus) infecting yam (Dioscorea spp.). The assay uses a set of six oligonucleotide primers targeting the YMV coat protein region, and the amplification products in YMV-positive samples are visualized by chromogenic detection with SYBR Green I dye. The CT-RT-LAMP assay detected YMV in leaf and tuber tissues of infected plants. The assay is 100 times more sensitive in detecting YMV than standard RT-PCR, while maintaining the same specificity

Determination of scanned virus-free potato planting materials by positive selection and screening of tubers from seed stores in the western highlands of Cameroon

Positive selection for the identification of virus–free potato planting material was evaluated in four locations in Cameroon. Leaves from asymptomatic plants were randomly collected, the plants marked and tubers collected four weeks later, and screened with DAS-ELISA for PLRV, PVY, PVA, PVX, PVS and PVM presence. Five viruses were prevalent in leaves while four prevalent in tubers. Potato virus M was highly prevalent in leaves and tubers while PVY was high only in leaves. Potato virus A was absent in both leaves and tubers while PVX was free only in tubers. A positive correlation was observed between virus prevalence in leaves and tubers (r=0.806). The prevalence of the six viruses in potato seed tubers from four seed stores was tested. Potato virus M was the most prevalent, while PLRV was the least. Small, medium and large tuber sizes were tested for the viruses, and infection rates decreased significantly the bigger the tuber size. Positive selection though not highly efficient can be recommended for resource-poor farmers, to control the economically important potato viruses. Tuber size can serve as a guide to identify healthy tubers, but must be combined with laboratory tests for effective use in selecting seeds for planting.Keywords: Potato viruses, virus-free tubers, positive selection

Gender topics on potato research and development.

Sustainable Development Goals 5 calls for addressing gender equality and women empowerment by, among other things, eliminating all forms of discrimination against women. At CIP we interpret this to mean strengthening the use of gender approaches in research and ensuring that research products are responsive to the needs of men and women. This chapter reviews lessons learnt over the years on integrating gender into potato research and development. The chapter discusses how gender has been approached in five key themes in potato research, namely (1) conserving and accessing genetic resources, (2) genetics and crop improvement, (3) managing priority pests and disease, (4) access to seed (seed flows and networks), and (5) marketing, postharvest processing and utilization. This chapter discusses how gender relations that favor men influence women’s participation in and their ability to benefit from potato production, marketing, and research for development. The review shows that potato research has been increasingly focusing on social determinants of potato farming because of the realization that purely technical solutions will not solve inefficiencies in potato production. Using a gender relations approach, the chapter attempts to draw out lessons that can contribute to the design of future potato interventions including research aimed at reducing the gender gap in agriculture in general and potato farming in particular