International Potato Center Lima

Lima, Peru

International Potato Center Lima

Lima, Peru

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Jenderek M.M.,U.S. Department of Agriculture | Ambruzs B.,U.S. Department of Agriculture | Tanner J.,U.S. Department of Agriculture | Holman G.,U.S. Department of Agriculture | And 4 more authors.
Acta Horticulturae | Year: 2014

In cryopreservation of germplasm, using dormant winter buds (DB) as source plant material is economically favorable over tissue culture options. Although the DB cryopreservation method has been known for many years, the approach is feasible only for cryopreserving a select number of temperate tree species. The original method developed for Malus (apple) DB, requires desiccation of stem segments (to 25-30% moisture content), slow cooling (to -30°C), storage in liquid nitrogen vapor (LNV) and viability testing by grafting. We investigated the possibility of using this method for cryopreservation of DB of Juglans regia, J. cinerea, Prunus dulcis, P. persica, Salix exigua and S. triandra germplasm. The post LNV viability of P. dulcis, P. persica and S. triandra DB was very low. Dormant buds of J. cinerea harvested in December were viable in a higher percent than buds harvested in January. The fraction of viable SalixDB on 10 cm branch segments was significantly higher (30 and 80%) than on 6 cm long segments (0 and 45%;P>0.05); this indicated that the longer segments might be more suitable for cryopreservation of thetwo Salix species. For Juglans regia, the viability after LNV exposure was evaluated by grafting and forced bud break under high relative humidity conditions and the percent of viable buds was similar forboth methods; hence testing under mist might be a valid indication of viability. The application of the Malus DB cryopreservation method might also be applicable to preservation of almond, peach and English walnut however studies on factors enhancing post LNV viability are needed.


Vollmer R.,International Potato Center Lima | Panta A.,International Potato Center Lima | Tay D.,International Potato Center Lima | Roca W.,International Potato Center Lima | Ellis D.,International Potato Center Lima
Acta Horticulturae | Year: 2014

The effect of shoot tip pre-culture on media with varying sucrose levels (0.0-0.6 M) followed by treatment with Plant Vitrification Solution 2 [PVS2] (15, 30, 45, 60 min) was evaluated with six sweet potato accessions [Ipomoea batatas (L.) Lam.], using the "PVS2-droplet vitrification" cryopreservation method. No significant differences in the percent of shoot regeneration were observed when shoot tips were pre-cultured on sucrose concentrations ranging from 0.1 to 0.4 M. The highest mean shoot regeneration rate of 57.7 ± 5.5% after rewarming from cryopreservation (+LN) was obtained with a sucrose concentration of 0.35 M. Intermediate exposure times in PVS2 of 30 and 45 min showed statistically better results than shorter or longer exposure, with a maximum mean shoot regeneration (+LN) of 68.5 ± 4.5% with a 30 min exposure. Screening a separate larger group of 24 sweet potato accessions with a 0.35 M sucrose pre-culture and 30 min PVS2 treatment (+LN) resulted in shoot formation rates ranging from 1.7 to 66%.


PubMed | International Potato Center Lima and Louisiana State University
Type: | Journal: Frontiers in plant science | Year: 2016

The challenge to produce more food for a rising global population on diminishing agricultural land is complicated by the effects of climate change on agricultural productivity. Although great progress has been made in crop improvement, so far most efforts have targeted above-ground traits. Roots are essential for plant adaptation and productivity, but are less studied due to the difficulty of observing them during the plant life cycle. Root system architecture (RSA), made up of structural features like root length, spread, number, and length of lateral roots, among others, exhibits great plasticity in response to environmental changes, and could be critical to developing crops with more efficient roots. Much of the research on root traits has thus far focused on the most common cereal crops and model plants. As cereal yields have reached their yield potential in some regions, understanding their root system may help overcome these plateaus. However, root and tuber crops (RTCs) such as potato, sweetpotato, cassava, and yam may hold more potential for providing food security in the future, and knowledge of their root system additionally focuses directly on the edible portion. Root-trait modeling for multiple stress scenarios, together with high-throughput phenotyping and genotyping techniques, robust databases, and data analytical pipelines, may provide a valuable base for a truly inclusive green revolution. In the current review, we discuss RSA with special reference to RTCs, and how knowledge on genetics of RSA can be manipulated to improve their tolerance to abiotic stresses.


PubMed | Indian International Crops Research Institute for the Semi Arid Tropics, University of Kassel, University of Hohenheim, Bioversity International NASC Complex New Delhi and 3 more.
Type: | Journal: Frontiers in plant science | Year: 2016

West Africa (WA) is among the most food insecure regions. Rapid human population growth and stagnating crop yields greatly contribute to this fact. Poor soil fertility, especially low plant available phosphorus (P) is constraining food production in the region. P-fertilizer use in WA is among the lowest in the world due to inaccessibility and high prices, often unaffordable to resource-poor subsistence farmers. This article provides an overview of soil P-deficiency in WA and opportunities to overcome it by exploiting sorghum and pearl millet genetic diversity. The topic is examined from the perspectives of plant breeding, soil science, plant physiology, plant nutrition, and agronomy, thereby referring to recent results obtained in a joint interdisciplinary research project, and reported literature. Specific objectives are to summarize: (1) The global problem of P scarcity and how it will affect WA farmers; (2) Soil P dynamics in WA soils; (3) Plant responses to P deficiency; (4) Opportunities to breed for improved crop adaptation to P-limited conditions; (5) Challenges and trade-offs for improving sorghum and pearl millet adaptation to low-P conditions in WA; and (6) Systems approaches to address soil P-deficiency in WA. Sorghum and pearl millet in WA exhibit highly significant genetic variation for P-uptake efficiency, P-utilization efficiency, and grain yield under P-limited conditions indicating the possibility of breeding P-efficient varieties. Direct selection under P-limited conditions was more efficient than indirect selection under high-P conditions. Combining P-uptake and P-utilization efficiency is recommendable for WA to avoid further soil mining. Genomic regions responsible for P-uptake, P-utilization efficiency, and grain yield under low-P have been identified in WA sorghum and pearl millet, and marker-assisted selection could be possible once these genomic regions are validated. Developing P-efficient genotypes may not, however, be a sustainable solution in itself in the long-term without replenishing the P removed from the system in harvested produce. We therefore propose the use of integrated soil fertility management and systems-oriented management such as enhanced crop-tree-livestock integration in combination with P-use-efficiency-improved varieties. Recycling P from animal bones, human excreta and urine are also possible approaches toward a partially closed and efficient P cycle in WA.

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