Response mechanism of sweet potato storage root formation and bulking to soil compaction and its relationship with yield

Intercropping, as a common worldwide cultivation pattern, provides opportunities for sustainable agriculture with fuller use of light, temperature and land resources and greater yield per unit of land. The intercropping impact on crop quality is a current focus. This study found that shading cultivation of purple-fleshed sweet potato can improve the storage root pigment accumulation by more than 20% to increase economic benefits. We performed gas chromatography and mass spectrometry analysis of storage roots of the anthocyanin-enriched cultivar Jihei-1 under 60% shading and nonshaded treatments. A total of 224 differential metabolites were identified, among which N-acetyl-5-hydroxytryptamine, 1-monopalmitin, 4-pyridoxic acid, dodecano, arbutin, tryptophan, citrulline and phenylalanine were significantly upregulated under shading with a more than 10-fold change. Furthermore, metabolic pathway enrichment maps were based on the biological processes and stratification level selected. These metabolites mainly influenced the pathways of phenylpropanoid biosynthesis, the citrate cycle, organic acid biosynthesis and metabolism and amino acid metabolism. Through tissue-specific dynamic changes in amino acids, soluble sugars, starch and anthocyanins during storage root development, we proposed a variety-specific strategy of purple-fleshed sweet potato in response to prolonged deep shading, that is, utilizing and enhancing broad aboveground-tissue photosynthesis and transferring photosynthates into roots in advance, leading to a rapid increase in storage root anthocyanin synthesis. With comprehensive qPCR, western blot and enzyme activity analyses, we identified three key enzymes, CHS, ANS and 3GT, in purple-fleshed sweet potato storage roots in response to shading, which affect the root anthocyanin content by influencing the flavonoid metabolism pathway. This study provides a theoretical basis for revealing the regulation of anthocyanin synthesis in crops and a guidance for high-quality sweet potato cultivation and nutritional improvement using shade facilities.

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Split Application under Reduced Nitrogen Rate Favors High Yield by Altering Endogenous Hormones and C/N Ratio in Sweet Potato

Agronomy ◽

10.3390/agronomy10091243 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1243

Author(s):

Xiangbei Du ◽

Xinyue Zhang ◽

Lingcong Kong ◽

Min Xi

Keyword(s):

Sweet Potato ◽

Root Formation ◽

Management Strategies ◽

Root Weight ◽

Storage Root ◽

Split Application ◽

Storage Roots ◽

N Content ◽

N Management ◽

Aba Content

A process for reducing the nitrogen (N) application rate while maintaining sweet potato yield urgently needs to be determined. A two-year pot experiment was conducted with three N management strategies to explore the mechanism underlying yield increase caused by a split application under a reduced N rate through an investigation of the changes in the carbon (C)-N metabolism and endogenous hormone. Results revealed that, compared with conventional basal N management, split application under a reduced N rate increased storage root yield by 22.1% through improving the storage root number and mean storage root weight by 12.3% and 10.2%, respectively. During the storage root formation period, split application under a reduced N rate decreased the soil-available N (AV-N) content and N content in storage root, inducing elevated C content, C/N ratio, auxin (IAA) content, zeatin and zeatin riboside (Z + ZR) content and reduced abscisic acid (ABA) content in storage roots, promoting storage root formation. During the storage root bulking period, split application under a reduced N rate appropriately elevated the soil AV-N content and N content in the storage root which, together with increased ABA content, which enhanced C content and C/N ratio in the storage root, resulted in an improved mean storage root weight. These results will facilitate the generation of appropriate N management strategies to improve sweet potato productivity.

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Influence of volatiles from healthy and decaying sweet potato storage roots on sclerotial germination and hyphal growth of Sclerotium rolfsii

Canadian Journal of Botany ◽

10.1139/b89-008 ◽

1989 ◽

Vol 67 (1) ◽

pp. 53-57 ◽

Cited By ~ 4

Author(s):

C. A. Clark

Keyword(s):

Sweet Potato ◽

Sclerotium Rolfsii ◽

Hyphal Growth ◽

Root Tissue ◽

Natural Soil ◽

Potato Storage ◽

Storage Root ◽

Storage Roots ◽

Sweet Potatoes ◽

Directional Growth

Volatiles released from sweet potato storage root tissue infected by different sweet potato storage root pathogens stimulated eruptive germination of sclerotia of Sclerotium rolfsii but did not influence the direction of hyphal growth on agarose. Volatiles from healthy sweet potato storage root tissue did not affect percent hyphal or eruptive germination of sclerotia of S. rolfsii but stimulated directional growth of hyphae toward the healthy tissue. In laboratory experiments, the frequency of infection of sweet potato stem segments by S. rolfsii on the surface of natural soil was increased when sclerotia were incubated in the presence of decaying sweet potato storage root tissue. Incidence of sclerotial blight lesions on sprouts in plant beds was increased in the presence of roots infected by Fusarium solani or Erwinia chrysanthemi. Volatiles from decaying sweet potato mother roots may predispose sweet potatoes to sclerotial blight.

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