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Life Sciences Commons

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Agricultural Science

South Dakota State University

Theses/Dissertations

2019

Articles 1 - 2 of 2

Full-Text Articles in Life Sciences

Nodule Zone-Specific Gene Expression In Soybean, Sadikshya Aryal Jan 2019

Nodule Zone-Specific Gene Expression In Soybean, Sadikshya Aryal

Electronic Theses and Dissertations

Nitrogen is one of the most limiting nutrients for plant growth and yield. Leguminous plants such as soybean (Glycine max) have developed the ability to form a symbiotic association with nitrogen fixing rhizobia. This symbiotic association results in the formation of unique structures called nodules that originate from root cortex via de novo cell differentiation. During soybean nodule development, two major nodule zones, the Nodule primordium (Npr) in the center and the nodule parenchyma (Npa) in the periphery, are clearly distinguishable. Npr gives rise to infection zone (IZ), and the Npa holds vascular bundles. However, it is not clear what …


Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson Jan 2019

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …