Effect of Restricted Root Growth on Carbohydrate Metabolism and Whole Plant Growth of Cucumis sativus L.

Roots of `Golden Girl' squash (Cucurbita pepo var. melopepo) and `Encore' cucumber (Cucumis sativus L.), 4- and 3-days-old, respectively, were exposed to 2, 6, 10, and 15C for 24, 48, 96, 144, and 192 hours to compare the sensitivity to chilling temperatures and the subsequent recovery at more favorable temperatures. Seedlings were more sensitive to chilling at 2 and 6C when measured by their ability to resume growth when returned to 26C. Root growth decreased after 48 hours of chilling. Seedlings stressed at 10 and 15C were able to continue root growth at these temperatures and when returned to 26C. However, seedlings at 10C exhibited root-tip browning in both crop species, suggesting disfunction in metabolic pathways that were repressed in seedlings growing at 2C where those symptoms were not present. Effects on root dry weight occurred in the first 24 hours at all temperatures studied. After 96 hours of treatment, seedlings grown at 2 and 6C were irreversibly damaged, as evidenced by their inability to resume growth when returned to 26C. Leakage of electrolytes from squash and cucumber roots increased after 48 hours at 2C. Potassium, Na+, and PO4-2 were lost in greater amounts than Mg+2, Cl-, and SO4-2. No difference in ionic leakage occurred at 10 and 15C, and Ca+2 leakage was not detected at any chilling stress temperature.

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Combination on endophytic fungal as the Plant Growth-Promoting Fungi (PGPF) on cucumber (Cucumis sativus)

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d220315 ◽

2021 ◽

Vol 22 (3) ◽

Author(s):

Syamsia Syamsia ◽

ABUBAKAR IDHAN ◽

AMANDA PATAPPARI FIRMANSYAH ◽

NOERFITRYANI NOERFITRYANI ◽

IRADHATULLAH RAHIM ◽

...

Keyword(s):

Secondary Metabolites ◽

Plant Growth ◽

Cucumis Sativus ◽

Endophytic Fungi ◽

Growth Promoter ◽

Growth Promoters ◽

Cucumis Sativus L ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Phosphate Solubilizing

Abstract. Syamsia S, Idhan A, Firmansyah AP, Noerfitryani N, Rahim I, Kesaulya H, Armus R. 2021. Combination on endophytic fungal as the Plant Growth-Promoting Fungi (PGPF) on Cucumber (Cucumis sativus). Biodiversitas 22: 1194-1202. Endophytic fungi are known to stimulate plant growth by producing secondary metabolites, including phytohormones (IAA and Gibberellins), siderophore, phosphate-solubilizing metabolites. In this study, a total of six endophytic fungi were successfully isolated from local rice plants and showed different abilities in producing secondary metabolites, during single isolates testing. These six isolates were then combined to obtain 15 combinations for analysis, to determine the best combination for application as a plant growth promoter. Subsequently, each combination was tested for phytohormones (IAA, gibberellins) and siderophore (quantitatively)-producing activity, phosphate-solubilizing ability, and the effect on cucumber (Cucumis sativus L) plant growth. F13 showed activity in producing IAA and produced the highest gibberellin levels, while F1 exhibited the highest phosphate-solubilizing activity. In addition, F11 (Na-salicylate) and F1 (catechol) showed the highest siderophore activity, while a combination of F6, F8, F9, and F12 successfully increased plant height growth. Also, F4 increased the root growth, while the fresh weight of cucumber was increased by F8 treatment, under controlled conditions. Molecular analysis showed the tested isolates have close similarity to Daldinia eschscholtzii, Sarocladium oryzae, Rhizoctonia oryzae, Penicillium allahabadense, and Aspergillus foetidus. The combination of endophyte fungal isolates showed potential as plant growth promoters, however, further testing on several plant types is required before the combination is to be widely applied.

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