scholarly journals Incidence of End Rots and Internal Necrosis in Sweetpotato Is Affected by Cultivar, Curing, and Ethephon Defoliation

2013 ◽  
Vol 23 (6) ◽  
pp. 886-897 ◽  
Author(s):  
Christopher A. Clark ◽  
Washington L. da Silva ◽  
Ramón A. Arancibia ◽  
Jeff L. Main ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Breeding Line ◽  
Storage Roots ◽  
Postharvest Storage ◽  
Breeding Lines ◽  
Multiple Environments ◽  
Internal Necrosis ◽  
Production Areas ◽  
And Storage

Two distinct syndromes have emerged in some production areas that have caused losses of sweetpotato (Ipomoea batatas) storage roots during postharvest storage: a complex of fungal rots (end rots) progressing from either end of storage roots and a necrotic reaction (internal necrosis) progressing internally from the proximal end of storage roots. This study was conducted in multiple environments to evaluate whether the use of preharvest ethephon application and storage with or without curing after harvest could be used to screen sweetpotato breeding lines for susceptibility/resistance to these two disorders. Treating vines with ethephon 2 weeks before harvest and placing harvested roots directly into storage at 60 °F without curing resulted in the greatest incidence of end rots in each state and there were significant differences in incidence among the sweetpotato genotypes evaluated. However, when ethephon was not used and roots were cured immediately after harvest, the incidence of end rots was low in all the genotypes evaluated except for one breeding line. Incidence and severity of internal necrosis were greatest when ethephon was applied preharvest and roots were cured immediately after harvest, but two cultivars, Hatteras and Covington, had significantly more internal necrosis than all others.

scholarly journals Effect of Cultivar, Ethephon, Flooding, and Storage Duration on Sweetpotato Internal Necrosis

2018 ◽  
Vol 28 (3) ◽  
pp. 246-251
Author(s):  
Peter J. Dittmar ◽  
Jonathan R. Schultheis ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Sushila Chaudhari ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Ipomoea Batatas ◽  
Storage Roots ◽  
Storage Duration ◽  
Overhead Irrigation ◽  
Significant Change ◽  
Internal Necrosis ◽  
And Storage

The reason for internal necrosis occurrences in sweetpotato (Ipomoea batatas) storage roots is not well understood. This disorder begins internally in the storage roots as small light brown spots near the proximal end of the root that eventually can become more enlarged as brown/black regions in the cortex. The objective of this study was to determine the effect of ethephon and flooding on the development of internal necrosis in the sweetpotato cultivars Beauregard, Carolina Ruby, and Covington over storage durations from 9 to 150 days after harvest (DAH) when roots had been cured. Soil moisture treatments were no-flooding, and simulated flooding that was created by applying 10 inches of overhead irrigation during 2 weeks before harvest. Ethephon was applied at 0, 0.75, and 0.98 lb/acre 2 weeks before harvest. Overall, ‘Covington’ and ‘Carolina Ruby’ had greater internal necrosis incidence (22% to 65% and 32% to 51%, respectively) followed by ‘Beauregard’ (9% to 22%) during storage duration from 9 to 150 DAH at both soil moistures. No significant change was observed for either internal necrosis incidence or severity for ‘Beauregard’ and ‘Carolina Ruby’ over the storage duration of 9–150 DAH. However, there was an increase of internal necrosis incidence and severity 9–30 DAH in ‘Covington’, with incidence and severity remaining similar 30–150 DAH. Storage roots in treatments sprayed with 0.75 or 0.98 lb/acre ethephon had higher internal necrosis incidence and severity compared with the nontreated, regardless of cultivars at both soil moistures. This research confirms that sweetpotato cultivars differ in their susceptibility to internal necrosis (incidence and severity), ethephon applied to foliage can contribute to internal necrosis development in storage roots, and internal necrosis incidence reaches a maximum by 30 DAH in ‘Covington’ and 9 DAH in ‘Carolina Ruby’ and ‘Beauregard’.

scholarly journals Sweetpotato Transplant Holding Duration Effects on Plant Survival and Yield

2017 ◽  
Vol 27 (6) ◽  
pp. 818-823 ◽  
Author(s):  
William B. Thompson ◽  
Jonathan R. Schultheis ◽  
Sushila Chaudhari ◽  
David W. Monks ◽  
Katherine M. Jennings ◽  
...  
Keyword(s):  
North Carolina ◽  
Ipomoea Batatas ◽  
Storage Root ◽  
Storage Roots ◽  
Higher Plant ◽  
Root Numbers ◽  
Dry Conditions ◽  
Plant Stand ◽  
And Storage ◽  
Lower Plant

Studies were conducted in North Carolina to determine the effect of holding durations (HDs) [0, 1, 3, 5, and 7 days before planting (DBP)] of ‘Covington’ sweetpotato (Ipomoea batatas) transplants on plant stand and storage root numbers and yield in production fields. In a second field study, the effect of preplant irrigation (PI) treatments (PI and nonirrigation) were evaluated along with the transplant HD on plant stand, storage root numbers, and yield. Transplants held for 7 DBP did not survive as well as the other treatments (lower plant stands) and had lower no. 1, marketable, and total storage root numbers and yields than other holding treatments. HD of 1 or 3 DBP resulted in higher plant stands, and no. 1, marketable, and total numbers of storage roots and yields than holding for 0, 5, or 7 DBP. This study affirms the importance of soil moisture at and shortly after planting for transplant survival and yield. Holding transplants for 1–3 DBP can improve stand establishment and yields when dry conditions occur either before or soon after planting. However, holding transplants for 7 DBP can result in reduced plant stands and yields when stress/dry conditions occur soon after planting.

scholarly journals Occurrence, Severity and Initiation of Internal Necrosis in ‘Covington’ Sweetpotato

2015 ◽  
Vol 25 (3) ◽  
pp. 340-348 ◽  
Author(s):  
Chen Jiang ◽  
Penelope Perkins-Veazie ◽  
Sylvia M. Blankenship ◽  
Michael D. Boyette ◽  
Zvezdana Pesic-VanEsbroeck ◽  
...  
Keyword(s):  
North Carolina ◽  
Relative Humidity ◽  
Ipomoea Batatas ◽  
Storage Temperature ◽  
The State ◽  
Storage Root ◽  
Storage Roots ◽  
Harvest Aid ◽  
Internal Necrosis ◽  
Storage Facilities

A series of studies were conducted to better understand the occurrence and causes of internal necrosis (IN) in ‘Covington’ sweetpotato (Ipomoea batatas). Assessment of the problem among the industry was done for 2 years and revealed that IN was widespread in commercial storage facilities throughout the state of North Carolina; both incidence and severity were generally low (<10% incidence with minimal severity of symptoms). A few storage rooms had a high percentage of IN with severe storage root symptoms but results were inconsistent across years and among rooms. Preharvest studies with commercially used insecticides did not induce IN, but the harvest aid ethephon consistently induced IN with an incidence higher than 50%. Internal necrosis symptoms were not detectable at harvest, and earliest consistent incidence was observed 6 days after harvest (DAH) during the curing phase. Symptoms became more prevalent and severe at 30 DAH. However, in commercial storage rooms, no relationship was found between IN incidence and postcuring storage temperature or relative humidity (RH) conditions. Sweetpotato storage roots stored in air-tight barrels and exposed to 100 ppm ethylene after curing showed no relationship between the presence of ethylene gas in storage and incidence of IN. Our results indicate that IN incidence of ‘Covington’ is erratic with no obvious cause among storage rooms and that initiation of IN may occur most frequently during the first week following harvest.

scholarly journals (250) Monogalactosyl-diglyceride Contents in Sweetpotato Clones

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1046D-1047
Author(s):  
Howard F. Harrison ◽  
Joseph K. Peterson ◽  
Maurice E. Snook
Keyword(s):  
Ipomoea Batatas ◽  
Saturated Fatty Acids ◽  
Total Content ◽  
Dry Weight ◽  
Storage Roots ◽  
Allelopathic Potential ◽  
Breeding Lines ◽  
Mass Spectral ◽  
Monogalactosyl Diglyceride ◽  
Root Tissues

Bioasssay-guided investigation of constituents possibly contributing to the allelopathic potential of sweetpotato led to the isolation of a nonpolar seed germination inhibitor in sweetpotato (Ipomoea batatas L.) roots. Mass spectral data supported by HPLC s pectroscopic analyses and data obtained from hydrolysis products revealed the presence of three monogalactosyl-diglycerides (MGDGs) (galactosyl-di-linoleneoyl glyceride, galactosyl-linoleneoyl-linoleoyl glyceride, and galactosyl-di-linoleoyl glyceride) in storage roots. The compounds inhibited proso millet germination, and at 100 ppm inhibition was about 90%. MGDG with fully saturated fatty acids (galactosyl-distearoyl glyceride) was not inhibitory in the bioassay. An efficient method for quantitation of individual MGDGs was developed, and the contents of each compound in the storage root tissues of 12 genetically diverse cultivars and breeding lines were determined. On a dry weight basis, total MGDG contents ranged between 107 and 452 μg/g in the periderm, 298 and 807 μg/g in the cortex, and 296 and 755 μg/g in the stele. Also, large differences in the ratios of the three compounds between clones and between tissues within a clone were noted. The differences between clones indicate that manipulating total content and ratios of MGDGs through plant breeding is feasible.

scholarly journals Sweetpotato `Beauregard' Mericlones Vary in Yield, Vine Characteristics, and Storage Root Size and Shape Attributes

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1089-1092 ◽  
Author(s):  
A.Q. Villordon ◽  
J.M. Cannon ◽  
H.L. Carroll ◽  
J.W. Franklin ◽  
C.A. Clark ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Maximum Yield ◽  
Storage Root ◽  
Storage Roots ◽  
Marketable Yield ◽  
Methods Of Evaluation ◽  
Foundation Seed ◽  
Axis Length ◽  
And Storage ◽  
Selection Of

Yield tests and evaluation of selected storage root and vine characters were conducted among 12 `Beauregard' sweetpotato [Ipomoea batatas (L.) Lam.] mericlones. Maximum yield differences were 43%, 48%, 79%, and 40% for U.S. #1, canners, jumbos, and total marketable yield, respectively. Additive main effect and multiplicative interaction (AMMI) biplot analysis was useful in graphically presenting the yield differences and stability patterns of mericlones. Differences were also detected in vine length, internode diameter, and internode length. Digital image analysis of U.S. #1 storage roots also revealed differences in storage root minor axis length, roundness, and elongation attributes. The results provide valuable information for enhancing current methods of evaluation and selection of mericlones for inclusion in sweetpotato foundation seed programs.

scholarly journals Vine Removal Prior to Harvest, and Curing Duration and Temperature Affect the Incidence and Severity of Internal Necrosis in ‘Covington’ Sweetpotato

2020 ◽  
Vol 30 (5) ◽  
pp. 544-551
Author(s):  
Fernando Montero de Espinosa Baselga ◽  
Jonathan R. Schultheis ◽  
Michael D. Boyette ◽  
Lina M. Quesada-Ocampo ◽  
Keith D. Starke ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Field Studies ◽  
Curing Temperature ◽  
Storage Roots ◽  
Physiological Disorder ◽  
Potash Fertilizer ◽  
Storage Room ◽  
Postharvest Treatments ◽  
Internal Necrosis ◽  
Lower Temperature

Internal necrosis (IN) is a physiological disorder that affects Covington, the most commonly grown sweetpotato (Ipomoea batatas) cultivar in North Carolina. Because IN affects the quality of sweetpotato storage roots, studies have been conducted since the first report of IN in 2006. Field studies (three in 2016 and two in 2017) were conducted to evaluate preharvest and postharvest treatments on the occurrence of IN in ‘Covington’ storage roots. Four preharvest treatments consisted of combinations of high chlorine or minimal chlorine potash fertilizer and mowing vs. not mowing before harvest. For postharvest treatments, 30 storage roots were obtained at harvest from each preharvest treatment plot and immediately cured in 75 and 85 °F rooms for a duration of 0.5, 1, 2, 3, and 5 weeks in 2016, and 0.5, 1, and 2 weeks in 2017. Shorter curing durations (0.5 and 1 week) coincided with industry recommendations while longer durations mimicked the challenges that some commercial facilities face when cooling down temperatures of rooms after curing is supposed to be concluded. Once curing temperature and curing duration treatments were completed, roots were placed in a 58 °F storage room at 85% relative humidity until cut. A control comparison was included in which harvested roots were placed in a 58 °F storage room (no curing) immediately after harvest. The storage roots from all temperature treatments were then cut 49 to 80 days after harvest, and incidence and severity of IN visually rated. Preharvest potash fertilizer treatments had minimal or no effect on occurrence of IN. However, mowing vines before harvest in several studies reduced IN incidence when roots were cured for more than 0.5 week at temperatures of at least 75 °F. Lower temperature (75 vs. 85 °F) and shorter curing duration (0.5 vs. 1, 2, 3, or 5 weeks) resulted in reduced IN occurrence in ‘Covington’ sweetpotato.

scholarly journals Metabolic diversity in sweet potato (Ipomoea batatas, Lam.) leaves and storage roots

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Margit Drapal ◽  
Genoveva Rossel ◽  
Bettina Heider ◽  
Paul D. Fraser
Keyword(s):  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Metabolic Diversity ◽  
Storage Roots ◽  
And Storage

scholarly journals Differential Expression of Genes between Storage Roots of Sweetpotato Cultivars Jewel and White Jewel

2006 ◽  
Vol 131 (6) ◽  
pp. 798-805 ◽  
Author(s):  
Cecilia E. McGregor ◽  
Don R. LaBonte
Keyword(s):  
Ipomoea Batatas ◽  
Large Scale ◽  
Differentially Expressed ◽  
Spontaneous Mutant ◽  
Storage Roots ◽  
Flesh Color ◽  
Carotene Content ◽  
Root Cells ◽  
And Storage ◽  
Β Carotene

`White Jewel' is a yellow-and-orange fleshed spontaneous mutant of the orange-flesh sweetpotato [Ipomoea batatas (L.) Lam.] cultivar Jewel. Mutations in storage root flesh color, and other traits are common in sweetpotato. The orange flesh color of sweetpotato is due to β-carotene stored in chromoplasts of root cells. β-carotene is important because of its role in human health. In an effort to elucidate biosynthesis and storage of β-carotene in sweetpotato roots, microarray analysis was used to investigate genes differentially expressed between `White Jewel' and `Jewel' storage roots. β-carotene content calculated from a* color values of `Jewel' and `White Jewel' were 20.66 mg/100 g fresh weight (FW) and 1.68 mg/100 g FW, respectively. Isopentenyl diphosphate isomerase (IPI) was down-regulated in `White Jewel', but farnesyl-diphosphate synthase (FPPS), geranylgeranyl diphosphate synthase (GGPS), and lycopene β-cyclase (LCY-b) were not differentially expressed. Several genes associated with chloroplasts were differentially expressed, indicating probable differences in chromoplast development of `White Jewel' and `Jewel'. Sucrose Synthase was down-regulated in `White Jewel' and fructose and glucose levels in `White Jewel' were lower than in `Jewel' while sucrose levels were higher in `White Jewel'. No differences were observed between dry weight or alcohol insoluble solids of the two cultivars. This study represents the first effort to elucidate β-carotene synthesis and storage in sweetpotato through large-scale gene expression analysis.

scholarly journals The Expression of IbMYB1 Is Essential to Maintain the Purple Color of Leaf and Storage Root in Sweet Potato [Ipomoea batatas (L.) Lam]

2021 ◽  
Vol 12 ◽  
Author(s):  
Daowei Zhang ◽  
Yongjun Tan ◽  
Fang Dong ◽  
Ya Zhang ◽  
Yanlan Huang ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Anthocyanin Biosynthesis ◽  
Expression Patterns ◽  
Anthocyanin Content ◽  
Storage Root ◽  
Storage Roots ◽  
Cultivated Species ◽  
Purple Color ◽  
And Storage

IbMYB1 was one of the major anthocyanin biosynthesis regulatory genes that has been identified and utilized in purple-fleshed sweet potato breeding. At least three members of this gene, namely, IbMYB1-1, -2a, and -2b, have been reported. We found that IbMYB1-2a and -2b are not necessary for anthocyanin accumulation in a variety of cultivated species (hexaploid) with purple shoots or purplish rings/spots of flesh. Transcriptomic and quantitative reverse transcription PCR (RT-qPCR) analyses revealed that persistent and vigorous expression of IbMYB1 is essential to maintain the purple color of leaves and storage roots in this type of cultivated species, which did not contain IbMYB1-2 gene members. Compared with IbbHLH2, IbMYB1 is an early response gene of anthocyanin biosynthesis in sweet potato. It cannot exclude the possibility that other MYBs participate in this gene regulation networks. Twenty-two MYB-like genes were identified from 156 MYBs to be highly positively or negatively correlated with the anthocyanin content in leaves or flesh. Even so, the IbMYB1 was most coordinately expressed with anthocyanin biosynthesis genes. Differences in flanking and coding sequences confirm that IbMYB2s, the highest similarity genes of IbMYB1, are not the members of IbMYB1. This phenomenon indicates that there may be more members of IbMYB1 in sweet potato, and the genetic complementation of these members is involved in the regulation of anthocyanin biosynthesis. The 3′ flanking sequence of IbMYB1-1 is homologous to the retrotransposon sequence of TNT1-94. Transposon movement is involved in the formation of multiple members of IbMYB1. This study provides critical insights into the expression patterns of IbMYB1, which are involved in the regulation of anthocyanin biosynthesis in the leaf and storage root. Notably, our study also emphasized the presence of a multiple member of IbMYB1 for genetic improvement.

scholarly journals RESPONSE OF OF SWEETPOTATO GROWN IN NFT TO DIFFERENT PHOTOPERIODS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 665f-665
Author(s):  
D. G. Mortley ◽  
C. K. Bonsi ◽  
W. A. Hill ◽  
P. A. Loretan ◽  
C. E. Morris ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Dry Weight ◽  
Root Number ◽  
Storage Root ◽  
Growth Responses ◽  
Storage Roots ◽  
Area Index ◽  
Chamber Studies ◽  
Growth Chamber Studies ◽  
And Storage

Growth chamber studies were conducted to determine growth responses of sweetpotato [Ipomoea batatas (L.) Lam) to differing photoperiods (PP) when grown by use of NFT. Four vine cuttings (15 cm length) of GA Jet and TI-155 were grown for 120 days at 12/12, 15/9, 18/6, and 21/3 light/dark PP. Irradiance averaged 427 umol m-2 s-1, with day/night temperatures of 28/22C and 70% RH. A modified half Hoagland's solution was used. Number of storage roots/plant, and storage root fresh and dry weights for GA Jet increased as PP increased from 12 to 21 h, while storage root fresh and dry weights for TI-155 increased up to 18 h PP but declined at 21 h PP. Storage root number/plant for TI-155 declined at 15 h PP but was higher at both 18 and 21 h PP. Highest foliage dry weight for GA Jet was obtained at 21 h PP while that for TI-155 was obtained at 18 h PP. Leaf area index (LAI) for GA Jet increased with increased PP, while LAI for TI-155 increased with increased PP up to 18 h then declined at 21 h PP.

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