International Potato Center

About: International Potato Center is a facility organization based out in Lima, Peru. It is known for research contribution in the topics: Population & Phytophthora infestans. The organization has 1036 authors who have published 1460 publications receiving 47183 citations.

Resistencia al Tizón Tardío de la papa (Phytophthora infestans) en Cruzamientos de Cultivares y Clones de Papa (Solanum tuberosum L.)

Abstract: Resumen es: Bajo condiciones de campo en el Valle de Toluca, Mexico, se estudio el grado de resistencia a P. infestans, los efectos de aptitud combinatoria general...

Identification of Natural Resistance Mediated by Recognition of Phytophthora infestans Effector Gene Avr3aEM in Potato.

Abstract: Late blight is considered the most renowned devastating potato disease worldwide. Resistance gene (R)-based resistance to late blight is the most effective method to inhibit infection by the causal agent Phytophthora infestans. However, the limited availability of resistant potato varieties and the rapid loss of R resistance, caused by P. infestans virulence variability, make disease control rely on fungicide application. We employed an Agrobacterium tumefaciens-mediated transient gene expression assay and effector biology approach to understand late blight resistance of Chinese varieties that showed years of promising field performance. We are particularly interested in PiAvr3aEM , the most common virulent allele of PiAvr3aKI that triggers a R3a-mediated hypersensitive response (HR) and late blight resistance. Through our significantly improved A. tumefaciens-mediated transient gene expression assay in potato using cultured seedlings, we characterized two dominant potato varieties, Qingshu9 and Longshu7, in China by transient expression of P. infestans effector genes. Transient expression of 10 known avirulence genes showed that PiAvr4 and PiAvr8 (PiAvrsmira2) could induce HR in Qingshu9, and PiAvrvnt1.1 in Longshu7, respectively. Our study also indicated that PiAvr3aEM is recognized by these two potato varieties, and is likely involved in their significant field performance of late blight resistance. The identification of natural resistance mediated by PiAvr3aEM recognition in Qingshu9 and Longshu7 will facilitate breeding for improved potato resistance against P. infestans.

Child Overweight or Obesity Is Associated with Modifiable and Geographic Factors in Vietnam: Implications for Program Design and Targeting

Abstract: Child overweight or obesity is increasing in most countries, including Vietnam. We sought to elucidate the drivers of child overweight or obesity in Vietnam and understand how they vary geographically. We compiled nationally representative cross-sectional data from the Vietnam Nutrition Surveillance Survey collected annually between 2012-2015 and household income data from the General Statistics Office. We used a quasi-Poisson log link function to calculate relative risks (RRs) of under-five child overweight or obesity for 13 variables and stratified analyses by child age ( 4000 g (RR: 1.66; 95% confidence interval (CI): 1.48, 1.86), maternal body mass index (BMI) ≥27.5 compared with BMI <23 (RR: 1.62; 95% CI: 1.47, 1.78), and living in the Southeast (RR: 2.06; 95% CI: 1.84, 2.30), Mekong River Delta (RR: 1.58; 95% CI: 1.41, 1.77), or Central South (RR: 1.54; 95% CI: 1.37, 1.74) compared with the Central Highland. A 20% higher provincial average monthly per capita income was associated with a 17.4% higher prevalence in child overweight or obesity (P < 0.0001, Adjusted R2 = 0.36). High birthweight and maternal BMI were strongly associated with child overweight or obesity but are not likely primary drivers in Vietnam, given their low prevalence. C-section delivery, sedentary lifestyle, high maternal education, urbanicity, and high household income affect a large proportion of the population and are, therefore, important risk factors. Policies and programs should target these factors and regions at greatest risk of overweight or obesity, particularly the Southeast and Mekong River Delta.

The effect of storage conditions on subsequent field performance of potato seed tubers in Tunisia

Abstract: Seed tubers of four cultivars were grown under similar conditions and harvested simulataneously. They were stored in traditional dark storage, diffused-light storage, or cold storage, and with combinations of these three methods for 150 or 230 days beginning in the hot, dry summer period. The effect of storage conditions on emergence, stem and tuber number, tuber size distribution and yield is discussed. Results suggest an optimal combination of storage method, cultivar choice, and sprout management practices may be achieved to obviate the need for cold storage in warm climates. Emergence and yield were consistently good for the 150-day storage period when traditional storage was followed by diffused-light storage. The sam technology gave promising results for the 230-day period with cultivars Claustar or Desiree when seed was desprouted prior to planting.

The inhibition of potato sprout growth by light. II: Effects of temperature and light intensity

Abstract: SUMMARY In an experiment with eight potato cultivars at Huancayo, Peru, storage of seed tubers in a prototype diffuse-daylight store resulted in a mean 17% increase in the yield of the subsequent crop, and in more rapid emergence of six of the cultivars after planting, as compared with seed stored in darkness. The dark-stored seed had very long sprouts that had to be removed at planting. In two experiments at Glasgow, Scotland, seed tubers of four cultivars were stored at a range of temperatures in darkness and artificial light. At the time of planting, some of the light-stored tubers were desprouted as well as the dark-stored ones, so that the effect of desprouting could be distinguished from any direct effect of storage in darkness. Desprouting consistently delayed emergence and senescence of the crop and in most cases reduced its yield. In 1983 the yield reduction was greatest in the first early cV. Home Guard after storage at high temperature (22 °C), when it was associated with low stem numbers and incomplete emergence. In 1984 after light storage at still higher temperature (22/33 °C) and desprouting, this cV. behaved similarly, but the corresponding dark-stored treatment yielded heavily after greatly delayed haulm senescence. CV. Desiree and, in 1984, cV. King Edward retained some apical dominance after storage at the lower temperatures and in some cases responded to desprouting with a small yield increase. In general desprouting after high-temperature storage reduced yields more than could readily be explained on the basis of the physiological age being reset to zero at planting.