Efficient Partially Replicated Designs for Multi-Environment Early-Generation Breeding Trials
摘要
Early-generation breeding trials (EGBTs) are usually performed as a part of selection process in order to achieve genetic improvement in plants. EGBTs examine many breeding lines with limited resources available in one or more environments. Replication of every line in every environment is often not possible due to resource constraints. Consequently, breeders opt for un-replicated trials, leading to less statistically reliable results. Partially replicated (p-rep) designs in multiple environments, where a proportion of the lines are replicated in each environment, offer an alternative. This paper presents two new methods for constructing series of p-rep designs that are suitable for multi-environmental trials. These designs are efficient and cost-effective in terms of resources as they require lesser replications and hence, they possess high application potential in EGBTs conducted over multiple environments. Further, an R-package “pRepDesigns” is developed that generates p-rep designs to facilitate the breeders for selecting appropriate designs. It is always possible to derive optimal PBIB designs from the proposed p-rep designs. A lower bound of mean square error for prediction of inbred performance is derived considering a random effects model under block set up.