Research Report 2019_20

Josh Clevenger, PhD / Clevenger Lab

Identifying selection targets for beneficial traits in peanuts

Clevenger’s team aims to fight these threats and create heartier peanut lines using genomics by employ- ing marker-assisted selection techniques. Quantitative traits, such as plant height or disease resistance, are controlled by genetic loci called quantitative trait loci (QTL). Identification of QTLs is important for crop breed- ing. By mapping a QTL controlling a favorable trait with a closely linked DNA marker and introducing the QTL into a plant line, plant offspring that inherit the desirable trait can be selected using the linked DNA marker. In a paper published in Crop Science in May 2020, Clevenger and his colleagues provide markers for marker-assisted selection for an important disease in peanut, called stem rot 1 . Soilborne pathogens like the fungus Sclerotium rolfsii cause stem rot, which typically reduces peanut yields by five to twenty percent. By per- forming QTL sequencing on stem rot resistant and sus- ceptible plants, the group identified and validated two QTL regions controlling stem rot resistance in peanut. The results from this study prove that QTL sequenc- ing can be used to successfully identify markers to select for resistance to a complex disease. Be- cause the study relied on historical data, it also shows that historical data can be used for QTL mapping which opens up many avenues to uti- lize previously collected data to develop new tools for breeding.

HudsonAlpha’s Center for Plant Science and Sustain- able Agriculture continued to grow in 2020 with the addition of two new faculty members. Faculty Investi- gator Josh Clevenger, PhD, brings his passion and ex- pertise in peanut breeding and genomics to the team. Clevenger came to HudsonAlpha from Mars Wrigley Chocolate, where he worked as a research scientist specializing in peanut genetic improvement.

Josh Clevenger, PhD

A major goal of Clevenger’s lab is to bridge the gap between science and nature by more rapidly introducing beneficial traits into cultivated crops farmers can plant on their land. To do this, his team is developing better computational tools to help identify selection mark- ers for the traits, and new, rapid breeding practices to introduce these markers into existing crop lines. Because of Clevenger’s nearly decade long experience with peanuts, they remain a major focus of his lab. Peanut is an important oil and food crop that is grown on millions of acres of land throughout tropical and subtropical regions worldwide. Peanut growers’ livelihood relies on a successful harvest yielding a max- imum number of peanuts per acre of land. Pests, fun- gi, toxins, and weather events such as drought, heavy periods of rain or late freezes, are all common threats to a successful peanut season. In order to combat these potential threats, farmers rely on fungicides, pesticides, fertilizers, and irrigation systems. However, these treat- ments and regimens are costly and time consuming.

Aflatoxins are produced by certain molds and threaten peanuts and other crops.


HudsonAlpha Institute for Biotechnology

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