The study was aimed to explore the photosynthetic characteristics and yield underground corm of Amorphophallus muelleri under different light conditions. Three intercrop modes of A. muelleri, pruned rubber tree intercrop mode T1 [forest center (T1M) and forest edge (T1S)], interrow mode of puelia T2[forest center (T2M) and edge (T2S)], 50% light transmittance shade mode T3M, no pruning rubber tree (CK)[forest center (CKM) and edge (CKS)] were used. The light intensity (Lux) and photosynthetically active radiation (PAR) in different light conditions were measured. The daily variation pattern of A. muelleri, photosynthetic parameters [net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), transpiration rate (Tr)], chlorophyll fluorescence parameters [maximum photochemical efficiency (Fv/Fm), actual photochemical quantum yield(YII), maximum electron transfer rate (ETRmax), half-saturation light intensity (Ik)], photosynthetic pigment parameters [chlorophyll a (Chl a), chlorophyll b(Chl b), total chlorophyll (Chl a+b), chlorophyll a/b (Chl a/b)] were measured at three stages (head changing stage, corm expansion stage, maturity stage). The yield of underground corm under different light conditions was compared. The results showed that daily variations of Lux and PAR were basically consistent under light conditions, showing “unimodal”modes. There were significant differences in the photosynthetic parameters (Pn, Gs, Tr, and Ci) among different light conditions. Compared with CK, Pn, Gs, and Tr of the T3M were the significantly highest in all three stages. During the head changing and corm expansion stages, Pn, Gs, Tr of the T1 and T2 were significantly higher than those of CK; The chlorophyll fluorescence parameters (Fv/Fm, YII, ETRmax, IK) of each light conditions were significantly higher than those of CK; The changes in photosynthetic pigment parameters (Chl a, Chl b, Chl a+b, Chl a/b) of various conditions were irregular. The Chl a, Chl b, Chl a+b of T2 and CK were higher than those of T1 and T3 at all three stages, and Chl a/b of all treatments was significantly higher than those of CK. From the comparison of light intensity and yield between the forest center and edge under conditions, it can be seen that the forest center is higher than the forest edge. After comparing the implementation effects of various intercropping modes, it can be seen that all treatments have improved the photosynthetic characteristics and yield of A. muelleri, while the pruned rubber tree modes T1 treatment is most obvious, and achieved the similar effect of single cropping under artificial shade. Therefore, in rubber tree production, pruning measures or other measures is needed to improve the light conditions and replace monoculture artificial shade for planting A. muelleri. The intercrop mode of puelia requires increase in fertilizer application and a reasonable allocation of crop distance direction to effectively alleviate the burns caused by direct sunlight on A. muelleri plants, and improve photosynthetic efficiency, thereby increasing crop yield and land use efficiency.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |