Over-exploitation associated changes in free radicals and its scavengers in Hevea brasiliensis

Raj Shammi, . and Alam Badre, . and Dey S. K., . and Sethuraj M. R., . and Das Gitali, . and Sen-Mandi Swati, . Over-exploitation associated changes in free radicals and its scavengers in Hevea brasiliensis. pp. 28-40. ISSN 1511-1768

Tapping panel dryness (TPD)syndrome generally considered an a stress-induced physiological disorder is a consequence of abnormal exploitation in rubber (Hevea brasiliensis). Numerous studies in other crops have revealed that stress induces/enhances the formation of free radicals (FR) which gets moped up by its scavenging system. To study the status of free radicals and its scavenging system during occurrence of TPD normal plants were subjected to frequent tapping and stimulation treatment (10 ethephon) to accelerate the occurrence of the syndrome. A significant negative correlation was observed between FR in the bark and superoxide dismutase (SOD)in the lutoid with tapping. However latex thiol showed a very low linear correlation with progression of tapping. The study also revealed that the amount of FR infrequently tapped plants (where the wounding was excessive) was less than that of in the stimulated plants though the damage to the scavenging system (SOD)was higher in the frequently tapped tree. It was also observed that with progression of time the percentage of TPD was more in the frequently tapped trees than in the stimulated ones. Interestingly however at the 115th actual tapping the occurrence of TPD was found to be higher in the stimulated samples than that of in the frequently tapped plants. The control plants showed no TPD syndrome in both cases. This implies that excess generation of active oxygen with defective defense mechanism (in terms of SOD) along with frequency of exploitation source-sink imbalance etc. may determine the yielding potential and the TPD incidence in rubber.

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Abstract

Tapping panel dryness (TPD)syndrome generally considered an a stress-induced physiological disorder is a consequence of abnormal exploitation in rubber (Hevea brasiliensis). Numerous studies in other crops have revealed that stress induces/enhances the formation of free radicals (FR) which gets moped up by its scavenging system. To study the status of free radicals and its scavenging system during occurrence of TPD normal plants were subjected to frequent tapping and stimulation treatment (10 ethephon) to accelerate the occurrence of the syndrome. A significant negative correlation was observed between FR in the bark and superoxide dismutase (SOD)in the lutoid with tapping. However latex thiol showed a very low linear correlation with progression of tapping. The study also revealed that the amount of FR infrequently tapped plants (where the wounding was excessive) was less than that of in the stimulated plants though the damage to the scavenging system (SOD)was higher in the frequently tapped tree. It was also observed that with progression of time the percentage of TPD was more in the frequently tapped trees than in the stimulated ones. Interestingly however at the 115th actual tapping the occurrence of TPD was found to be higher in the stimulated samples than that of in the frequently tapped plants. The control plants showed no TPD syndrome in both cases. This implies that excess generation of active oxygen with defective defense mechanism (in terms of SOD) along with frequency of exploitation source-sink imbalance etc. may determine the yielding potential and the TPD incidence in rubber.

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Item Type:	Article
AGROVOC Term:	Overexploitation
AGROVOC Term:	Hevea brasiliensis
AGROVOC Term:	Tapping
AGROVOC Term:	Stress
AGROVOC Term:	Free radicals
AGROVOC Term:	Superoxide dismutase
AGROVOC Term:	Stimulation
AGROVOC Term:	Susceptibility to dryness
AGROVOC Term:	Physiological disorders
AGROVOC Term:	Abnormal function (physiology)
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	24 Apr 2025 06:28
URI:	http://webagris.upm.edu.my/id/eprint/23168

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