High frequency regeneration from grapevine petioles: Extension to new genotypes

Auxins were found to enhance shoot organogenesis when used in a high cytokinin medium at low levels. This enhancement was genotype specific. In the presence of 10.0 µM BA, Vanessa regenerated best with the inclusion of 4.0 µM IAA-dl-aspartate, while Catawba regenerated best with 2.0 µM IAA-glycine in the medium. With Ravat 51, 14-15% of explants regenerated in the presence of either 2.0 µM IAA-glycine or 4.0 µM IAA-dl-aspartate, whereas there was no regeneration in the absence of auxin. Tests with 0.0-8.0 µM TDZ as a cytokinin source indicated that petiole explants of Vanessa regenerate best (10%) at 4.0 µM TDZ. Our results clearly show that high cytokinin media can be easily extended to petiole explants of other genotypes to facilitate shoot organogenesis and that low levels of auxins, especially IAA conjugates can enhance the level of regeneration

Use of differential thermal analysis to quantify bud cold hardiness of grape selections and clones

Differential thermal analysis (DTA) was used to characterize primary bud mid-winter cold hardiness of Vitis spp. Bud hardiness reached a maximum and was rather stable during the months of January and February at Geneva, New York. Because cold tolerance increases during periods of prolonged cold, observed freezing temperature was adjusted on the basis of the freezing temperature of cv. Concord on the day of observation. DTA gives reproducible and meaningful estimates of bud freezing temperature. Such data account for at least 50 % of the among-cultivar variance in overall vine cold hardiness

Genetic Analysis of Restriction Fragment Length Polymorphisms in Vitis

The parents and progeny from two crosses (Cayuga White x Aurore and NY62.136.2 x Yates) were examined for the presence of DNA restriction fragment length polymorphisms (RFLPs). Seventeen independent DNA sequences were used in the analysis, 15 obtained from a grape Pstl genomic library and two heterologous probes obtained from other laboratories. Most of the low copy cloned sequences hybridized to more than two restriction fragments, possibly reflecting the polyploid nature of the Vitis genome. Nine of the probes detected RFLPs between parents. Analysis of the progenies (F1generation) revealed segregation for nine distinct polymorphisms generated by seven of the probes.Thus, a relatively high level of polymorphism among parents, as well as heterozygosity within each parent, was evident. Most RFLPs gave segregation ratios close to the 1: 1 ratio predicted for a locus heterozygous in one parent. However four differences between parental phenotypes did not segregated in the progeny, and in three instances fragments present in both parents segregated in the progeny. These peculiar results may be explained by accounting for heterozygosity or homozygosity, respectively, for the DNA segment that generates the polymorphism. We conclude that RFLP studies can be performed on the first filial generation in woody perennials such as Vitis that have a relatively high level of heterozygosity in the genom

Inheritance of chloroplast DNA in two full-sib Vitis populations

The mode of transmission of chloroplasts in 2 grape populations was determined using restriction fragment length polymorphisms of chloroplast DNA (cpDNA) to trace the origin of plastids in the progeny. The populations examined were formed by crossing 2 complex interspecific hybrids: NY 62.136.2 x Yates and Cayuga White x Aurore. Analysis of the restriction banding patterns of total DNA of the 4 parents probed with cpDNA of grape and petunia revealed a high level of polymorphism (63 %) between parents ot the first cross and a low level of polymorphism (15 %) between the parents of the second cross. The restriction banding patterns of the 4 parents were unique, indicating that there were 4 distinct chloroplast genotypes. Analysis of the restriction banding patterns of total DNA of the progeny probed with cpDNA showed that all progeny from both crosses exhibited the banding pattern of the maternal parent. Thus, the mode of plastid transmission in these populations of grape was strictly maternal

Characterization of RAPD markers in Vitis

A study was initiated to investigate the possibility of using RAPD markers in related populations of Vitis. We also sought to design primers that could amplify translation initiation sites (Kozak sequence) as a mean to maximize the production of RAPD markers from single copy DNA sequences in the genome. RAPD bands were labeled and used as probes on blots with either genomic DNA or RAPD products from cvs Aurore, Cayuga White, Horizon and Illinois 547-1. Reamplification of excised RAPD products produced either several bands of smaller size, a single band of smaller size or a single band of the same size as the original band. Among 16 probes hybridized to genomic DNA blots, three probes, including one from the Kozak primer amplification, hybridized to 1-2 bands, 5 probes hybridized to 3-8 bands and 8, including two from a Kozak primer reaction, to more than 10 bands on the genomic DNA blots. Twelve RAPD bands were also probed on RAPD blots derived from the RAPD reaction that produced each probe. Three of those probes hybridized to 1-2 bands, 8 hybridized to 3-8 and one hybridized to more than 10 bands indicating the presence of probe sequences in more than one RAPD band as amplified with the same primers. This result and the observations on reamplification of RAPD bands support the hypothesis that some of the longer RAPD fragments harbor internal priming sites that are either not amplified unless the reaction mixture is saturated with longer other primers indicating amplification from the same sequence but different sized repetitive DNA. RAPD reactions were also run with 16 primers on parental DNA of 2 crosses used in genetic mapping (Cayuga White x Aurore and Horizon x Illinois 547-1). These reactions rated 140 bands; 100 bands were shared by both populations, including 47 polymorphic bands. Ten polymorphic bands in Cayuga White x Aurore and 22 in Horizon x Illinois 547-1 were population specific. The RAPD analysis as well as hybridization of RAPD markers to the genomic blots suggest that linkage analysis could be used in related segregating populations with carefully chosen markers. Tagging single copy regions with Kozak-sequence-derived primers may be possible, but the low number of probes tested and lack of DNA sequence information prevents any definite conclusions

Herding Livestock – the Phoenix Rises from the Ashes? Digital Herding as a Future Tool for Grazing Livestock

Today, sustainable management of grazing livestock requires high efforts in management and fencing. Nowadays, several developments in digital technologies for herding grazing animals are arising. We conducted a systematic review on current developments in digital technologies for managing grazing animals within the landscape. We mainly focused on cattle (Bos taurus) and sheep (Ovis aries). We highlight the most promising developments of virtual fencing used in recent research to evaluate effectiveness, animal behaviour and welfare. Moreover, we highlight current research in digital herding by drones and robots. We discuss the potential and current limitations of digital tools for sustainable grazing management. Recent study results showed that virtual fences are highly efficient in keeping cattle within allocated pasture areas. So far, there has been no evidence for harmful impacts on animal welfare or reduction in animal performance. First findings suggest that drones can also herd and move animals. However, knowledge on the efficiency and potential effects on animal welfare when using drones is limited. First findings have shown that robots are able to gather animals to a specific location and heart-rate and blood tests showed that the animals were less stressed by the robot than they were by a human. However, research on herding drones and robots is still in its infancy. Digital tools provide the opportunity for precise livestock movement control and could facilitate the implementation of both productive and biodiversity-friendly grazing