Evaluation of a potato leafhopper (PLH) resistant alfalfa cultivar effects on PLH injury in alfalfa: grass mixed stands with and without insecticide.

The combination of a resistant cultivar and a grass resulted in significantly better PLH control than did the resistant cultivar alone or the grass alone. The resistant cultivar had 36% fewer PLH than the susceptible cultivar; however, the number of PLH was significantly higher than for the plots that were sprayed with insecticide (average less than 1 PLH per sub-plot). The untreated plot with the lowest PLH damage score was the resistant alfalfa/grass mixture (score = 1.8), whereas the resistant cultivar alone scored 2.4 and the susceptible cultivar alone and with grass averaged 3.5

GENERAL COMBINING ABILITY EFFECTS FOR REPRODUCTIVE HEAT TOLERANCE IN SNAP BEAN

GENERAL COMBINING ABILITY EFFECTS FOR REPRODUCTIVE HEAT TOLERANCE IN SNAP BEA

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long-term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field-scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm-scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM-ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country

A Conversation with Royse P. Murphy

QuickTime videos of the interview use H.264 compression. One set is for Apple TV and the other is formatted for the iPhone (and QuickTime Player).Abstract: Royse Peak Murphy, native of Norton, Kansas and survivor of the Dust Bowl experience, the Great Depression, then World War II, joined the Cornell Faculty in 1946. His main focus has been plant breeding, releasing many new crop varieties and supervising graduate studies for 21 Ph.D. students and 12 Master of Science students. His international work was extensive. He is an exemplary member of the Cornell University Faculty and served Cornell as a Department Head, Dean of the University Faculty (1964-67) and as a faculty member serving on the Board of Trustees. As has been characteristic of Murph since his ‘retirement’ 32 years ago and despite his recent physical adversities, he has maintained a vigorous devotion to and love for plant breeding – as witnessed by his participation in this video. Interviewed by plant breeder colleague, Donald R. Viands, he discusses his recollections of the plant breeding department at Cornell, supplementing his book on that subject, Evolution of Plant Breeding at Cornell University (http://dspace.library.cornell.edu/handle/1813/23087). Running time: 41 minutes. A biographical sketch by Lee B. Kass, that was presented at the celebration of his 90th birthday, is also included.1_aekcrmix1_v7jlyfi

Evaluation of a potato leafhopper (PLH) resistant alfalfa cultivar effects on PLH injury in alfalfa: grass mixed stands with and without insecticide.

The combination of a resistant cultivar and a grass resulted in significantly better PLH control than did the resistant cultivar alone or the grass alone. The resistant cultivar had 36% fewer PLH than the susceptible cultivar; however, the number of PLH was significantly higher than for the plots that were sprayed with insecticide (average less than 1 PLH per sub-plot). The untreated plot with the lowest PLH damage score was the resistant alfalfa/grass mixture (score = 1.8), whereas the resistant cultivar alone scored 2.4 and the susceptible cultivar alone and with grass averaged 3.5

Seeking Alfalfa Resistance to a Rhizophagous Pest, the Clover Root Curculio (Sitona hispidulus F.)

Since the cancellation of broad-spectrum soil-active insecticides in alfalfa (Medicago sativa L.) production, clover root curculio (Sitona hispidulus F.) (CRC) larval root damage has increased. Current CRC management practices are limited in their ability to suppress larval feeding belowground. First, we field screened developmental alfalfa populations for CRC damage. Subsequently, we developed a soil-less arena to observe nodule feeding and development (head capsule width) of larvae in the lab. This method was used to evaluate five alfalfa populations (two CRC-susceptible (control) and three CRC-resistant populations) against larvae. Further, one CRC-resistant population paired with its genetically similar susceptible population were tested against adult leaf consumption and oviposition in the greenhouse. Field screening revealed that the alfalfa populations selected for little or no larval root feeding damage were more resistant to CRC larval feeding than their corresponding unselected cultivars and significantly more resistant than populations selected for susceptibility. The development of a soil-less arena provided a useful method for evaluation of root-larva interactions. Although larval development was similar across susceptible and resistant alfalfa populations, one CRC-resistant population (NY1713) displayed overall increased nodulation and, thus, had a significantly lower proportion of nodules consumed by larvae. Adult feeding and oviposition aboveground were similar across all populations tested. These results provide possible candidates and screening method for the development and evaluation of alfalfa cultivars that may reduce the impacts of larval feeding and that offer an additional option for CRC management

Expected Values of Mean Squares for a Diallel Crossing Design with Maturity Groups

25 pages, 1 article*Expected Values of Mean Squares for a Diallel Crossing Design with Maturity Groups* (Federer, Walter T.; Ahmed, Mohammed B.; Viands, Donald R.) 25 page

Genome-Wide Associations with Resistance to Bipolaris Leaf Spot (Bipolaris oryzae (Breda de Haan) Shoemaker) in a Northern Switchgrass Population (Panicum virgatum L.)

Switchgrass (Panicum virgatum L.), a northern native perennial grass, suffers from yield reduction from Bipolaris leaf spot caused by Bipolaris oryzae (Breda de Haan) Shoemaker. This study aimed to determine the resistant populations via multiple phenotyping approaches and identify potential resistance genes from genome-wide association studies (GWAS) in the switchgrass northern association panel. The disease resistance was evaluated from both natural (field evaluations in Ithaca, New York and Phillipsburg, Philadelphia) and artificial inoculations (detached leaf and leaf disk assays). The most resistant populations based on a combination of three phenotyping approaches—detached leaf, leaf disk, and mean from two locations—were ‘SW788’, ‘SW806’, ‘SW802’, ‘SW793’, ‘SW781’, ‘SW797’, ‘SW798’, ‘SW803’, ‘SW795’, ‘SW805’. The GWAS from the association panel showed 27 significant SNPs on 12 chromosomes: 1K, 2K, 2N, 3K, 3N, 4N, 5K, 5N, 6N, 7K, 7N, and 9N. These markers accumulatively explained the phenotypic variance of the resistance ranging from 3.28 to 26.52%. Within linkage disequilibrium of 20 kb, these SNP markers linked with the potential resistance genes included the genes encoding for NBS-LRR, PPR, cell-wall related proteins, homeostatic proteins, anti-apoptotic proteins, and ABC transporter