Development of computational models for the purpose of conducting individual livestock and premises traceback investigations utilizing National Animal Identification System-compliant data

Many of the efforts surrounding the development of the National Animal Identification System have encompassed the identification of livestock production and handling premises as well as individuals or herds of animals, whereas little effort has been directed toward the ultimate goal of animal traceback within 48 h. A mock data set representative of the Colorado cattle population was created for modeling of cattle traceability. Using this data set, algorithms were developed to complete rapid and accurate traceback and traceforward of animals or premises or both. On July 19, 2005, the Colorado Department of Public Health and Environment, in conjunction with the Colorado Department of Agriculture, conducted a test exercise pertaining to homeland security. The exercise team randomly identified animal number 926,583 (of the 2 million total animals) as a potentially infected animal of interest and requested a traceback of this animal. Traceback was accomplished in 215 s, and 540 primary coresident animals were identified. However, due to animal movements, the number of coresidents (animals exposed, directly or indirectly, to the animal of interest) expanded with coresidency level (level 1 = direct contact; level 2 = direct contact with an animal that had direct contact with the animal of interest; level 3 = direct contact with an animal that had contact with an animal that had direct contact with the animal of interest, etc.) to more than 1.2 million coresidents at level 4, and more than 90% of all animals identified as a coresident at some level. In addition to the coresidency results, the premises containing the coresidents were identified and sorted by the number of coresidents. Because of animal movement, all 19,391 premises included in the data set had coresidents at some level. This exercise demonstrated the capability of the developed algorithms to complete rapid traceback and the complexity of the resulting animal traceback output.     

Functional genomics of microspore embryogenesis

Isolated plant microspores, when stressed and cultured in vitro, can be diverted from their normal gametophytic pathway towards sporophytic development, with the formation of haploid embryos and ultimately doubled-haploid plants. This process is called androgenesis or microspore embryogenesis, and is widely used in plant breeding programmes to generate homozygous lines for breeding purposes. Protocols for the induction of microspore embryogenesis and the subsequent regeneration of doubled haploid (DH) plants have been successfully developed for more than 200 species. These practical advances stand in stark contrast to our knowledge of the underlying molecular genetic mechanism controlling this process. The majority of information regarding the genetic and molecular control of the developmental switch from gametophytic to sporophytic development has been garnered from four intensely studied (crop) plants comprising two dicotyledonous species, rapeseed (Brassica napus) and tobacco (Nicotiana tabacum), and two monocotyledonous species, wheat (Triticum aestivum) and barley (Hordeum vulgare). In these species the efficiency of microspore embryogenesis is very high and reproducible, making them suitable models for molecular studies. In the past, molecular studies on microspore embryogenesis have focussed mainly on the identification of genes that are differentially expressed during this developmental transition and/or early in embryo development, and have identified a number of genes whose expression marks or predicts the developmental fate of stressed microspores. More recently, functional genomics approaches have been used to obtain a broad overview of the molecular processes that take place during the establishment of microspore embryogenesis. In this review we summarise accumulated molecular data obtained in rapeseed, tobacco, wheat and barley on embryogenic induction of microspores and define common aspects involved in the androgenic switch.     

The Giemsa C-Banded Karyotype of Canada Wildrye (Elymus canadensis)

Karyotype of Canada wildrye (Elymus canadenisis L.) was described using giemsa C-banding techniques. Most of the chromosomes showed dome banding pattern polymorphism. Small to large terminal and centormere bands were observed in most of the chromosomes. A faint satellite was observed in one chromosome. Tow chromosomes had a large interstitial band near the centromeres in the long arms. The Giemsa C-banding pattern of E. Canadensis is compared to that of Pseudoroegneria spicata and Critesion boddanii to illustrate species relationship.     

Production of interspecific hybrids between Glycine max and G. tomentella through embryo culture

Summary Interspecific hybrids have been obtained in an incompatible cross between Glycine max and G. tomentella through the in vitro culture of hybrid embryos. The percentage of successful pod setting in the crosses averaged 12.8% but there were marked differences depending on the soybean cultivar used as the female parent. Hybrid embryos at globular to heart stages were extracted from the embryo sac 15–25 days after pollination and cultured in vitro. Hybrid plants were successfully obtained by culturing the embryos on B5 medium supplemented with 0.1 mg/l IBA followed by culture on B5 medium supplemented with 0.1 mg/l TBA plus 0.25 mg/l 2-iP. The F1 plants resembled the wild male parent in growth form, but had an intermediate leaf shape between that of the parents.     

Evaluating maize growth models “CERES-Maize” and “IXIM-Maize” under elevated temperature conditions

It would be preferable to use a reliable crop growth model for studies on climate change impact assessment. The objectives of this study was to evaluate simulation performance for two maize models, including CERES-Maize and IXIM models, included in the DSSAT model (version 4.6) in terms of phenology and yield. Two early maturing cultivars, Chalok#1 and Junda# 6, were grown under controlled environment in plastic houses at Suwon, Korea. Each cultivar, which was sown at four different date in 2013 and 2014, was subjected to four sets of temperature conditions including ambient (AT), AT+1.5°C, AT+3°C, and AT+5°C. In simulations of phenology under given conditions, the anthesis date and grain filling ratio were underestimated, especially when temperature was unusually high, e.g., in 2013. The maize models also had poor accuracy in grain yield, which resulted from the fact that these models had relatively large errors in simulation of kernel number and kernel weight under elevated temperature conditions. In addition, both models were not able to simulate the drastic decrease of kernel number due to heat stress around flowering periods. These results indicated that two maize models would need improvements in simulation of crop response to supra-optimal temperature before they would be used to assess the impact of the climate change on maize yield. This studies merits further study to improve algorithms in phenology simulation at supraoptimal temperature.     

A molecular technique for selection of self-compatible varieties of Japanese pear (Pyrus pyrifolia Nakai)

The pear cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄; sm = stylar-part mutant) has been used as a parent to breed self-compatible cultivars that produce excellent fruits. However, determination of the self-compatibility of ‘Osa-Nijisseiki’ offspring requires a lot of time, 6 years or more, by conventional cross breeding. We have designed a rapid reliable method for the identification of self-compatible varieties of ‘Osa-Nijisseiki’ offspring based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) with S-allele specific restriction endonucleases. By using this method, 8 self-compatible varieties were selected among 16 selections resulting from a cross between the self-compatible cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄) and the self-incompatible cultivars ‘Niitaka’ (S₃S₉), ‘Whasan’ (S₃S₅), ‘Chuwhangbae’ (S₄S₆). The S-genotypes of 16 ‘Osa-Nijisseiki’ offsprings were also determined. This revised version was published online in August 2006 with corrections to the Cover Date.