American Journal of Potato Research最新文献

Abstract

In Ecuador, farmers poorly adopt practices to manage potato seed degeneration. This could be related to the deficient understanding of the farmers’ capacity to experience seed degeneration and respond to it. We contribute to this understanding by answering: How do farmers experience seed degeneration?; What practices do farmers implement when their seed is degenerated?; and Is experiencing degeneration the pivotal factor determining how farmers replace their seed regardless their income? We analysed data collected in Ecuador through farmers’ focus group discussions, farmers’ surveys and interviews, and the Ecuadorian employment status survey. We found that approximately half of the farmers experienced degeneration. Farmers experienced it through low yields, change in seed appearance, crop weakening, and seed physiological problems. When farmers experienced degeneration, they replaced their seed, sought for technical advice, applied more agricultural inputs, or grew other crops. Income was an important trigger for farmers to change their seed replacement practices.

Potato market value is heavily affected by tuber quality traits such as shape, color, and skinning. Despite this, potato breeders often rely on subjective scales that fail to precisely define phenotypes. Individual human evaluators and the environments in which ratings are taken can bias visual quality ratings. Collecting quality trait data using machine vision allows for precise measurements that will remain reliable between evaluators and breeding programs. Here we present TubAR (Tuber Analysis in R), an image analysis program designed to collect data for multiple tuber quality traits at low cost to breeders. To assess the efficacy of TubAR in comparison to visual scales, red-skinned potatoes were evaluated using both methods. Broad sense heritability was consistently higher for skinning, roundness, and length to width ratio using TubAR. TubAR collects essential data on fresh market potato breeding populations while maintaining efficiency by measuring multiple traits through one phenotyping protocol.

Abstract

Abstract

Abstract

Genome-wide markers enable routine confirmation of whether varieties are true-to-type, and when they are not, to infer their identity. The objective of this study was to determine the basis of a previously described chromosome translocation, tr8-7, which was apparently polymorphic among holdings of the tetraploid potato (Solanum tuberosum L.) cultivar Desiree. Through analysis of publicly available genotype data from North American and European tetraploid potato germplasm, we resolved a longstanding mistaken identity of the United States Potato Genebank holding of Desiree, which is actually a somatic mutant of its maternal parent, cv. Urgenta. Comparison of multiple holdings revealed that tr8-7 was a somatic mutation that occurred at least 25 years ago and was maintained in isolated lineages. Holdings from other institutions lacked tr8-7 and were confirmed as Desiree by trio analyses, suggesting that the mixup affected the United States Potato Genebank and institutions that received Desiree from there. In the face of inevitable mutations and human error, we recommend validation of potato germplasm collections with pedigree and genomic information. To that effect, we provide molecular markers to distinguish the varieties investigated in this study.

Highly variable and unpredictable precipitation in humid regions makes water management important for consistent potato production. This study assessed the influence of supplemental irrigation (SI) and soil dewatering on potato productivity and profitability in Prince Edward Island, Canada. The average yields of Russet Burbank (RB), Shepody, Kennebec and Goldrush cultivars from 2000 to 2020 (excluding 2018) were conceptualized as the results of an un-replicated experiment with growing season (GS) precipitation representing water supply treatment. GS precipitation varied from 155 to 479 mm, with an average of 338 mm. Yield increased with increasing GS precipitation in the 155–257 mm range (Rainfall Zone 1; 3/20 seasons), became relatively insensitive to GS precipitation in the 258–425 mm range (Rainfall Zone 2; 12/20 seasons), and decreased as GS precipitation increased from 426 to 479 mm (Rainfall Zone 3; 5/20 seasons). Yields responded to GS precipitation following second-order polynomial regressions, with GS precipitation explaining 69%, 65%, 29% and 50% of yield variation for RB, Shepody, Kennebec and Goldrush cultivars, respectively. These yield regression equations predict that SI using a center-pivot system would produce a positive profit in the first half of Rainfall Zone 1 regardless of field size and in the second half of Rainfall Zone 1 in fields over 40 ha. SI would not produce a positive profit in Rainfall Zone 2 regardless of field size because precipitation was high enough that additional water supply would not have resulted in sufficient yield gains to offset the cost of SI. Soil dewatering would be beneficial for optimal production in Rainfall Zone 3 in which precipitation was excessive. The annual variation in precipitation, unpredictability of SI requirements, and unprofitability in most seasons, present a significant financial barrier for the widespread implementation of SI. On the other hand, the gross income gained from increased yields by soil dewatering would fully cover the cost of tile drain installation after only two to three extremely wet seasons, making tile drainage a good investment for consistent production. This study demonstrates that historical rain-fed yield and weather data can be used to assess the economics of potato production with SI and soil dewatering, and provides important insights on potato water management in a humid temperate climate.

For many years, potato seed lots have been tested for economically important pathogens in order to restrict their spread. Despite this, some pathogens inevitably make it into commercial fields and require management. Although knowledge about pathogen prevalence in commercial seed lots has increased over the last decade, assessment of the tuber necrotic viruses, Tobacco rattle virus and Potato mop-top virus, has been lacking. For seven years, four tubers from each seed lot in the Washington State University Seed Lot Trial were assessed for these two viruses. Tobacco rattle virus levels were negligible, but 1.76 to 5.50% of seed lots were infected with Potato mop-top virus each year. Potato mop-top virus was found in seven seed growing regions and 23 cultivars. These results are concerning, as the rate of transmission from seed to daughter tubers is largely unknown, and fields across the region are infested with Spongospora subterranea, the vector of Potato mop-top virus.

In response to increasing interest in diploid potato (Solanum tuberosum) breeding and the production of diploid inbred hybrid potato varieties, the Breeding and Genetics section of the Potato Association of America (PAA) organized a symposium on diploid breeding that took place during the 2021 PAA annual meeting. Proceedings from that symposium are documented in this manuscript. Speakers from academia, government and industry presented their unique perspectives. Presentations covered a wide range of topics. Potential advantages of diploid breeding were introduced, and reasons to be skeptical about diploid breeding were highlighted. The impact that diploid breeding might have on the potato seed industry was discussed. Advantages for genetics research were emphasized. Aspects of tomato breeding and production were reviewed and considered as potential models for diploid potato breeding and production activities. Lastly, an industry-centered view of diploid potato breeding was provided. Taken together, these presentations are a snapshot of how diploid potato breeding was viewed in the moment, a vision for how diploid breeding might be implemented, and a thoughtful reflection on how diploid breeding and inbred hybrid varieties might change the potato variety development process and impact the potato industry.