Storage roots of `Beauregard' and `Centennial' were used to identify varietal differences in fatty acid composition in plasmalemma lipids during storage conditions. Total plasmalemma fatty acid composition of glycolipids and phospholipids in storage roots of `Beauregard' and `Centennial' did not differ. The fatty acid composition of MGDG and DGDG in storage root plasmalemma was >50% unsaturated fatty acids in `Beauregard'. The high percentage of 18:2 (65.44%) fatty acid compared to `Centennial' (19.70%) and 79.35% total unsaturated fatty acid content in MGDG may contribute to low temperature tolerance in `Beauregard'. The higher percentages of 16:1 and 22:1 fatty acids in `Centennial' compared to `Beauregard' contributed to MGDG fatty acid unsaturation. However, these fatty acids have not been related to chilling tolerance.
Arambage Abesinghe and James O. Garner
Kalavathy Padmanabhan, Daniel J. Cantliffe, Roy C. Harrell and Dennis B. McConnell
A comparison of external morphology captured via a computer vision system and a study of internal anatomy of sweetpotato somatic embryos identified five different major morphological variants among torpedo and cotyledonary stage embryos. These included 1) Perfect Type, 2) Near Perfect Type, 3) Limited/No Meristematic Activity Type, 4) Disrupted Internal Anatomy Type, 5) Proliferating Type. Perfect and Near Perfect types of somatic embryos were categorized as competent, while Limited/No Meristematic activity, Disrupted Internal Anatomy, and Proliferating types were categorized as noncompetent with respect to their conversion ability. Lack of organized shoot development in somatic embryos of sweetpotato was attributed to the following abnormalities: 1) lack of an organized apical meristem, 2) sparsity of dividing cells in the apical region, 3) flattened apical meristem, 4) multiple meristemoids and/or diffuse meristematic activity throughout the embryo. A morphological fate map of most of the torpedo and cotyledonary embryo variants was identified, which will be beneficial in synthetic seeding and transgenic research and development of sweetpotato.
V.A. Khan, C. Stevens, M.A. Wilson, J.Y. Lu, E.G. Rhoden, D.J. Collins and J.E. Brown
In 1995 a study was conducted in split-split-plot design to determine the effect of single, double, and equilateral planting configurations with a single and double recommended rate of fertilizer (NPK), would have on the yield of four sweetpotato cultivars. TU-1892, Jewel, TU-82-155, and Georgia Jet were planted on a raised shaped bed 2 ft wide. Fertilizer was banded in the center of the bed and plants were then placed 6 inches away on both sides of this band for the double and equilateral configurations and on one side for the single configuration. Plants were spaced 12 inches apart within rows and the rate of fertilizer used for both single and double rows was the recommended rate for single rows. All plots were side dressed with an additional 80 lbs/acre of K at the time of flowering. Marketable yield data showed that by doubling the recommended rate of fertilizer yield increased for all cultivars which ranged from 26%-41% for single, 35%-88% for double, and 64%-104% for equilateral configurations, respectively. The results also indicated that net returns for TU-1892 was 217%, Jewel 136%, TU-82-155 203%, and Georgia-Jet 171%, for double and equilateral configurations, respectively, when the rate of fertilizer was doubled.
David Wees, Philippe Seguin, Josée Boisclair and Chloé Gendre
, Birmingham, AL Novak, B. Žutić, I. Toth, N. Dobričević, N. 2007 Sweet potato [ Ipomoea batatas (L.) Lam] yield influenced by seedlings and mulching Agr. Conspectus Scientificus 72 357 359 Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) 2010
Chen Jiang, Penelope Perkins-Veazie, Sylvia M. Blankenship, Michael D. Boyette, Zvezdana Pesic-VanEsbroeck, Katherine M. Jennings and Jonathan R. Schultheis
., Lincolnshire, IL Kitinoja, L.A. 1987 Effects of low concentrations of ethylene on sweetpotatoes ( Ipomoea batatas (L.) Lam) during curing and storage Acta Hort. 201 37 42 Kushman, L.J. 1975 Effect of injury and relative humidity during curing on weight and
Howard F. Harrison Jr, Trevor R. Mitchell, Joseph K. Peterson, W. Patrick Wechter, George F. Majetich and Maurice E. Snook
acids (DCQAs) isolated from Ipomoea batatas and I. pandurata . Proso millet seed germination bioassay. Test compounds were dissolved in 0.5 mL of MeOH and were pipetted into 35-mm disposable petri dishes containing a filter paper
Joshua K. Craver, Chad T. Miller, Kimberly A. Williams and Daniel L. Boyle
result of chemical stimulation Missouri Bot. Garden Annu. Rpt. 16 125 148 Trotter, A. 1904 Intumeszenze fogliari di “Ipomoea batatas.” Ann. Bot. (Lond.) 1 362 364 Wallace, R.H. 1928 Histogenesis of intumescences in the apple induced by ethylene gas Amer
William B. Thompson, Jonathan R. Schultheis, Sushila Chaudhari, David W. Monks, Katherine M. Jennings and Garry L. Grabow
A research gap exists on the effects of irrigation, transplant (nonrooted stem cuttings) size, and planting depth on sweetpotato (Ipomoea batatas) plant survival and storage root yield. Field studies were conducted in 2012 and 2013 to determine the effects of preplant irrigation, planting depth, and transplant size on sweetpotato plant stand, storage root number, and yield. Treatments included four transplant sizes (3.7, 6.3, 8.5, and 10.7 inches), two planting depths (2 and 6 inches), and preplant irrigation or nonirrigation. Overall, plant stand, storage root number, and yield were greater when transplants of size ≥6.3 inches were planted 6 inches deep as compared with transplants planted 2 inches deep. The use of preplant irrigation had an overall positive impact on plant stand, storage root number, and yield under dry soil conditions. When moisture was readily available, neither plant stand nor storage root numbers were affected by the application of irrigation as observed in 2013. However, sweetpotato yields were greater during both years when preplant irrigation was used. Irrigation during the root initiation phase of plant establishment or extended periods of no rainfall would be beneficial for improving plant stands and yields.
Alba J. Collart, Stephen L. Meyers and Jason K. Ward
Skinning of sweetpotato (Ipomoea batatas) storage roots is one of the greatest concerns of sweetpotato producers. Although skinning injury is very common, the severity of the injury can vary widely. At an undefined threshold, sweetpotatoes with skinning injury are no longer sold for fresh consumption. The objectives of this study were to examine how skinning injury influences consumers’ willingness-to-pay (WTP) for sweetpotatoes and to identify differences in valuations when the extent of skinning injury is labeled. Image analysis was used to quantify skinning injury and then an incentive-compatible, nonhypothetical laboratory experimental auction was conducted to collect data on consumers’ WTP for five categories of sweetpotatoes: 0% to <1% skinning injury, 1.0% to 3.0%, 3.1% to 5.0%, 5.1% to 7.5%, and 7.6% to 10.0%. On average, consumers were willing to pay the most for sweetpotatoes with 0% to <1% skinning injury (up to $1.51/lb to $1.67/lb) and the least for sweetpotatoes with 7.6% to 10% (up to $0.76/lb to $0.85/lb), yet mean WTP values were nonzero for all skinning levels. Moreover, when the extent of skinning was labeled (relative to when they bid blindly), consumers were willing to pay price premiums for sweetpotatoes with low skinning injury levels (0% to 5%) and discounted sweetpotatoes with the highest skinning injury level (7.6% to 10.0%), suggesting that skinning levels of 7.6% and above may not be acceptable by consumers.
A.Q. Villordon, C.A. Clark, R.A. Valverde, R.L. Jarret and D.R. LaBonte
Previous work by our group has detected the presence of a heterogeneous population of Ty1-copia-like reverse transcriptase retrotransposon sequences in the sweetpotato genome. Recently, we detected the presence of putatively active Ty1-copia-like reverse transcriptase sequences from a virus-infected `Beauregard' sweetpotato clone. In the current study, we report the differential detection of putatively stress-activated sequences in clones from seedling 91-189. The clones were infected with different combinations of virus isolates followed by extraction of leaf RNA samples at three sampling dates (weeks 2, 4, and 6) after inoculation. After repeated DNAse treatments to eliminate contaminating DNA, the RNA samples were subjected to first strand cDNA synthesis using random decamer primers followed by PCR analysis utilizing Ty1-copia reverse transcriptase-specific primers. Through this approach, we detected amplified fragments within the expected size range (280-300 bp) from clones infected with isolates of sweetpotato leaf curl (SPLC) and feathery mottle viruses (FMV) (week 2 and 6) and FMV (week 4). We were unable to detect PCR products from the noninfected clones or the other infected samples. The data suggests that specific viruses may be involved in the expression of these Ty1-copia-related reverse transcriptase sequences. It also appears that sampling at various dates is necessary to detect putative activity over time. This preliminary information is essential before proceeding to the construction and screening of cDNA libraries to isolate and fully characterize the putatively active sweetpotato Ty1-copia-like retrotransposon sequences. Through the partial or complete characterization of sweetpotato Ty1-copia elements, sequences that correspond to cis-regulatory element(s) can be identified and further studied for their roles in responding to specific stress factors.