کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5769790 | 1628784 | 2017 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Photosynthesis of Oil Palm (Elaeis guineensis) Photosynthesis of Oil Palm (Elaeis guineensis)](/preview/png/5769790.png)
- There are >107,000Â km2 of Oil Palm (Elaeis guineensis) plantations in SE-Asia.
- Photosynthesis measured using Pulse Amplitude Modulation Fluorometry (PAM).
- Photosynthesis measured in seedling (<1Â y), juvenile (1Â y) and adult (>5Â y) Oil Palm.
- Oil Palm is a classic sun plant with high photosynthetic rates at high irradiances.
- Maximum photosynthetic efficiency and photosynthesis in plants about midday.
Oil Palm (Elaeis guineensis) plantations cover more than 107,000 km2 in SE-Asia but there is little information on its photosynthetic characteristics. Photosynthesis in seedling, juvenile and adult Oil Palm (6 months, 1-2 y and >5 y old, respectively) were measured using blue-diode Pulse Amplitude Modulation Fluorometry (PAM). The Absorptance Factor of the leaves (Abt465nm) was measured using a Reflectance Absorptance Transmission (RAT) meter to calculate actual, rather than relative Electron Transport Rates (ETR). Midday measurements in juvenile and adult Oil Palm tree were: maximum quantum yield of Photosystem II (Ymax) in juveniles was about 0.63, Optimum irradiance (Eopt) was â300 μmol photon mâ2 sâ1. The maximum ETR (ETRmax) of juvenile plants was 24.06 ± 1.69 μmol eâ mâ2 sâ1: based on 4eâ/O2 this is equivalent to a maximum Photosynthetic Oxygen Evolution Rate (POERmax) of 89.21 ± 6.25 μmol O2 mg Chl aâ1 hâ1. Adult Oil Palm plants have a Ymax similar to juveniles but Eopt was â600 μmol photon mâ2 sâ1. The ETRmax of adult plants was 58.97 ± 2.07 μmol eâ mâ2 sâ1: or POERmax = 305.3 ± 10.7 μmol O2 mg Chl aâ1 hâ1. Oil Palm is a classic sun plant with high photosynthetic rates at high irradiances. Photosynthetic efficiencies (α0) were high for C3 sun plants: α0 in adult plants (0.272 ± 0.018 eâ photonâ1) was higher than juvenile plants (0.204 ± 0.034 eâ photonâ1) expressed on a leaf surface area basis and on a Chl a basis (1.406 ± 0.093 vs. 0.757 ± 0.124 O2 photonâ1 m2 g Chl aâ1). In juvenile and adult plants Eopt, POERmax and α0 tend to maximize about midday. In seedlings, Eopt and POERmax are highest in the early morning but maximum α0 is at about midday. Oil Palms strategically optimize photosynthesis for high irradiances and manipulate their photosynthesis vs. irradiance characteristics during the course of daylight.
Journal: Scientia Horticulturae - Volume 214, 5 January 2017, Pages 34-40