A global-temporal analysis on Phytophthora sojae resistance-gene efficacy.

Plant disease resistance genes are widely used in agriculture to reduce disease outbreaks and epidemics and ensure global food security. In soybean, Rps (Resistance to Phytophthora sojae) genes are used to manage Phytophthora sojae, a major oomycete pathogen that causes Phytophthora stem and root rot (PRR) worldwide. This study aims to identify temporal changes in P. sojae pathotype complexity, diversity, and Rps gene efficacy. Pathotype data was collected from 5121 isolates of P. sojae, derived from 29 surveys conducted between 1990 and 2019 across the United States, Argentina, Canada, and China. This systematic review shows a loss of efficacy of specific Rps genes utilized for disease management and a significant increase in the pathotype diversity of isolates over time. This study finds that the most widely deployed Rps genes used to manage PRR globally, Rps1a, Rps1c and Rps1k, are no longer effective for PRR management in the United States, Argentina, and Canada. This systematic review emphasizes the need to widely introduce new sources of resistance to P. sojae, such as Rps3a, Rps6, or Rps11, into commercial cultivars to effectively manage PRR going forward.

Reproductive performance of sows selected for divergent social genetic effects for growth

Social genetic effects (SGE) are genetic effects of an individual that affect the phenotype of its social partners. We determined the reproductive consequences of selection for SGE on growth in pigs. To investigate the influence of social genetic effects on growth, giltswere divided into two groups based on their estimated SGE: positive SGE sows (+SGE) and negative SGE sows (-SGE). At the time of selection, gilts were contemporaries and similarly managed. We recorded the reproductive performance of the two groups based on parity until culling. Reproductive performance included the total number of piglets born (TNB), number of piglets born alive (NBA), average piglet birth weight(BW), coefficient of variation for birth weight (CVBW), age at first farrowing (AFF), weaning to estrus interval(WEI), and gestation length (GL). TNB was 0.5 higher for +SGE sows (13.8) than for -SGE sows (P = 0.03, SEM = 0.06), and NBA exhibited a higher tendency in +SGE sows (P = 0.07, SEM = 0.06). Positive SGE for growth was expressed a tan earlier AFF (P = 0.04, SEM = 1.10), and shorter WEI (P < 0.01, SEM = 0.08) and GL (P = 0.03, SEM = 0.03). Collectively, the results of this study highlight the opportunities to improve litter size, the age at first farrowing, gestation length, and weaning to estrus interval using SGE.

Reproductive performance of sows selected for divergent social genetic effects for growth

Social genetic effects (SGE) are genetic effects of an individual that affect the phenotype of its social partners. We determined the reproductive consequences of selection for SGE on growth in pigs. To investigate the influence of social genetic effects on growth, giltswere divided into two groups based on their estimated SGE: positive SGE sows (+SGE) and negative SGE sows (-SGE). At the time of selection, gilts were contemporaries and similarly managed. We recorded the reproductive performance of the two groups based on parity until culling. Reproductive performance included the total number of piglets born (TNB), number of piglets born alive (NBA), average piglet birth weight(BW), coefficient of variation for birth weight (CVBW), age at first farrowing (AFF), weaning to estrus interval(WEI), and gestation length (GL). TNB was 0.5 higher for +SGE sows (13.8) than for -SGE sows (P = 0.03, SEM = 0.06), and NBA exhibited a higher tendency in +SGE sows (P = 0.07, SEM = 0.06). Positive SGE for growth was expressed a tan earlier AFF (P = 0.04, SEM = 1.10), and shorter WEI (P < 0.01, SEM = 0.08) and GL (P = 0.03, SEM = 0.03). Collectively, the results of this study highlight the opportunities to improve litter size, the age at first farrowing, gestation length, and weaning to estrus interval using SGE.(AU)