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| Author(s): |
Neriane Hijano
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Jaboticabal. 2020-06-23. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2020-04-24 |
| Advisor: | Pedro Luis da Costa Aguiar Alves; Silvano Bianco |
| Abstract | |
- Sugarcane cultivars planted nowadays are a result of genetic enhancement that aimed for productivity improvement; however, this diminished the species' competitive potential, which could be associated with the allelochemicals present or released by each variety. The Poaceae family resides among the most studied families regarding allelochemicals, hydroxamic acids amid them. Allelopathy is characterized by the influence of one plant on the growth and establishment of another plant through the production and release of secondary metabolites to the environment. This way, the objective was to assess interference and characterize the allelopathic potential of sugarcane, CTC 2 and IAC 911099 cultivars, through the root exudation release method; identify hydroxamic acids released by root exudation; isolate fractions and active substances of sugarcane. The plant in coexistence method is used to evaluate the interference between sugarcane and weed, in boxes with and without root interference, with weed species Ipomoea hederifolia (morning glory), Urochloa decumbens (signal grass) e Amaranthus viridis (slender amaranth). The evaluation of possible phytotoxic effect of root exudate is assessed by the evaluation of germination and development of the species Lactuca sativa (lettuce), Solanum lycopersicum (tomato), I. hederifolia, U. decumbens and A. viridis planted in sand that previously contained seedlings of sugar cane. To identify the hydroxamic acids BOA, MBOA, DIBOA and DIMBOA the root exudates were gathered from the sprouting of sugarcane in a sand tray, which was further washed and filtered for analysis in GC-MS. To isolate substances with allelopathic potential, leaves and roots were freeze-dried and prepared for bioassay. The most active extract was fractioned and the fractions analyzed by GC-MS-FID. The bioactive fractions were analyzed to identify the existing substances. For the experiment of sugarcane in coexistence with weed, the ‘CTC 2’ cultivar may have some allelopathic effect on A. viridis, I. hederifolia and U. decumbens and 'IAC 911099' on A. viridis and U. decumbens. Through the results acquired germinating seeds in substrates which previously contained sugarcane, possibly allelopathic substances were observed by root exudation, with ‘IAC 911099’ showing inhibitory effect over L. sativa and U. decumbens, and ‘CTC 2’ over L. sativa. Under the assessed conditions, root exudates from sugarcane cultivars CTC 2 and IAC911099 displayed no detectable quantities of BOA, MBOA, DIBOA and DIMBOA. For the leaves and roots, alpha-linolenic acid and linoleic acid were identified as bioactive and these caused growth inhibitions of L. sativa and Agrostis stolonifera and cellular leakage of Cucumis sativus. (AU) | |
| FAPESP's process: | 17/09011-6 - Sugarcane alelopatic potential evaluation |
| Grantee: | Neriane Hijano |
| Support Opportunities: | Scholarships in Brazil - Doctorate |