Phenotypic Plasticity Of Phyllostanchys Glauca In Limestone Mountain

Phyllostachys glauca is the dominant species in the limestone mountains in Northwest Jiangxi Province. At present, the adaptive strategy of the Ph. glauca to the high heterogeneity habitat of limestone mountains remains unknown. According to the classification of limestone habitat, the habitats were divided into three types, which were sporadic soil(SS), semi continuous soil(SCS) and continuous soil(CS). To explore the adaptive strategy of Ph. glauca, we investigated the phenotypic plasticity of Ph. glauca in different habitats. Then the variation in morphology, biomass allocation and anatomical structure of Ph. glauca were analyzed. The main results are as follows:(1) The plasticity change in morphology and root system of Ph. glauca is remarkable. In SS, the ramet of Ph. glauca was greater than that of SCS and CS. The basal diameter in SS was 3.05 cm, while it was 2.08 cm in CS. Compared with the CS, the brunching number was greater in SS and SCS(p=0.000<0.05), as well as the specific leaf area(p=0.002<0.05). The diameter of rhizome reached the highest value in CS, and the number of rhizome bud had the greatest value n SCS(p=0.008<0.05). With the increasing continuity of soil, the total root biomass, total root length and fine root number reduced, and the specific root length increased.(2) The biomass allocation of Ph. glauca in different habitats showed obvious plasticity capacity. With the increasement of soil consecutive, the ramet density raised and the ramet biomass of Ph. glauca declined. The ramet biomass in SS was 2.22 kg, which was 1.43 and 2.8 times of SCS and CS. The ramet density of Ph. glauca was 2.52 ramet/m2 in SS, 3.79 ramet/m2 in SCS and 4.49 ramet/m2 in CS respectively. The biomass allocation of Ph. glauca in limestone mountain indicated significant difference. In the SS, there had greater stem and root biomass allocation and lower leaf biomass allocation.(3) The Ph. glauca modified the anatomical structures to adapt the different habitat in the limestone mountain. Ph. glauca in the SS had larger leaf thickness, cuticle thickness, mesophyll thickness and vasular bundle tube area. Meanwhile, the root anatomical structure showed that Ph. glauca had well-developed sclerenchyma and parenchyma tissue, while the pericycle account for less of the root in SS. On the contrary, the root of Ph. glauca in CS had well-developed pericycle, while the parenchyma tissue account for less of the root.The results showed that the morphology, biomass allocation and anatomic structure of Ph. glauca in limestone mountain have noticeable plasticity. The ramet biomass and density was probably related to the soil distribution. Compared with SCS and CS, the Ph. glauca in SS show lower leaf biomass allocation, higher stem biomass allocation, thicker leaf and stratum corneum and enhanced root parenchyma of root. Those characteristics were connected with the function of reducing water loss and increasing water storage. Hence, the further research should focus on the structure characteristics related to moisture physiological adaptability, to reveal the relationship of structure and function of Ph. glauca in limestone mountain.