Influence of Water Regimes and Potassium Chlorate on Floral Induction, Leaf Photosynthesis and Leaf Water Potential in Longan

Abstract

This study verifies the influence of water regimes and potassium chlorate (KC1O 3 ) on photosynthetic rate, flower emergence and media moisture content of longan trees. The trees were grown in 150 liters lysimeter tanks filled with fine sand. The experimental design was a 2x2 factorial in completely randomized design (CRD) with 2 factors; 1) two levels of water regimes (well-watered and water deficit) and 2) two levels of KClO 3 at 10 and 0 g. The results revealed that the well-watered treatment produced faster days of terminal bud break than that of the water deficit treatment. The 10 g KClO 3 treatment induced 91 % flower emergence at 35 days after commencing the treatment, while the 0 g KClO 3 treatment had 82 % leaf flushing and had no flower emergence. Water deficit or KClO 3 treatments reduced the net carbondioxide (CO 2 ) exchange, transpiration and stomatal conductance rates. Moreover, the combination of well-watered and 0 g KClO 3 treatments gave the greatest values of the parameters. The well-watered treatment had higher volumetric water content in the growing medium and leaf water potential than the water deficit treatment, while for the 10 g and 0 g KClO 3 treatments had similar the media moisture content.

Floral Induction of Longan (Dimocarpus longan) by Potassium Chlorate: Application, Mechanism, and Future Perspectives

“…KClO 3 treatment can induce stress responses in leaves. These stress responses include reduced leaf water potential, net CO 2 assimilation, transpiration, stomatal conductance rates and F v / F m , increased destruction of photosynthetic apparatus, malondialdehyde and reactive oxygen species contents, and superoxide dismutase and peroxidase activities ( Figure 2 ; Ouyang et al, 2005 ; Sritontip et al, 2013 ). KClO 3 treatment can also cause changes in carbon and nitrogen nutrition in longan leaves.…”

“…It is speculated that appropriate amounts of KClO 3 can lead to stress responses. Reduced net carbon dioxide (CO 2 ) assimilation, transpiration, stomatal conductance rates, and photosystem II efficiencies (F v /F m ) have been detected after KClO 3 treatment (Hegele et al, 2008;Sritontip et al, 2010Sritontip et al, , 2013. The treatment has resulted in chlorophyll degradation, the destruction of chloroplast thylakoid membrane structure, the disappearance of chloroplast starch granules, and the destruction of basal granules (Lu, 2005).…”

Physiological Response of Wheat to Chemical Desiccants Used to Simulate Post-Anthesis Drought Stress

“…Differences between drought and desiccant effects could be attributed to their different modes of action, as KClO 3 is an oxidative reagent and is phytotoxic to all green tissues, and has been implicated in reducing the efficiency of photosystem II [29].…”

Transcriptome sequencing and DEG analysis in different developmental stages of floral buds induced by potassium chlorate in <i>Dimocarpus longan</i>

“…Some experiments on the mechanism of potassium chlorate induction of flower initiation have been conducted, but mostly at the physiological level, with unconvincing outcomes (Hegele et al 2008(Hegele et al , 2004Huang et al 2006;Potchanasin et al 2009aPotchanasin et al , 2009bSritontip et al 2013). Thus, more research is required at the molecular level.…”