Study On Morphological,anatomical And Physiological Activity Of Xanthoceras Sorbifolia Bunge

This paper takes the woody oil plant Xanthoceras sorbifolia Bunge as the research object,aiming to deeply explore its anatomical structure and physiological functions.Taking the vegetative organ of the fruit as the entry point,its anatomical structure was studied by paraffin sections.By analyzing its internal structure and physiological function,the characteristics of its anatomical structure and ecological adaptability were revealed.The effects of drought-rehydration treatment on the physiological activities of Wenguan fruit seedlings were studied by setting different drought grades with water content greater than 60%,water content50%～60%,water content 40%～50%,water content 30%～40%and different rehydration times on the 1st,5th,7th and 10th days of the annual Wenguan fruit seedlings.The results are as follows:1.Leaf bud duration,leaf stage,flowering period and long duration.The stomata were only distributed in the lower epidermis,and the apparatus was irregular.The shape of the upper and lower epidermal cells is irregular,and the vertical walls of the epidermal cells are flat-arcuate and shallow wavy.The leaf was composed of epidermis,mesophyll and vein,and the mesophyll parenchyma was divided into palisade tissue and spongy tissue is bifacial leaf.The upper and lower epidermis cells each have 1 layer,oval shape,closely arranged,and covered with a thicker corneum.Palisade tissue consists of 2 layers of cells closely arranged.Spongy tissue consists of3-4 layers of cells and is relatively loose.The main veins consists of mechanical tissue,ground tissue and vascular bundle.The main vein protrudes downward and is semicircular.There were two vascular bundles in the main vein,both of which were collateral vascular bundles,and xylem catheters were abundant and large in diameter.One vascular bundle was larger near the lower epidermis.The other vascular bundle is smaller near the upper epidermis.There were a lot of crystal clusters and mucilage cells around the vascular bundles of leaves.The petiole is composed of epidermis,ground tissue and vascular bundle.Epidermal hairs grow on the epidermis that cover the cuticle.Vascular bundle developed,xylem vessel number is more,the two vascular bundles contain rich ergastic substance between.Large amounts of phloem fibers exist within the petiole.2.The primary stem consists of epidermis,cortex and vascular cylinder.The epidermis consists of a single layer of tightly packed cells.The epidermis is covered with the corneum and has a epidermal hair.The cortex is thick and consists of 8-10 layers of cortical cellula mucosaparenchyma.The vascular bundle is unclosed collateral bundle.The vascular bundle composed of primary xylem,primary phloem and fascicular cambium.Vascular bundle developed,arranged around the pith in 1 round,vessel,large number,large diameter,developed pith,mostly accounted for a larger proportion of the stem.The vessels of the primary stem were spiral vessel and pitted vessel.According to the primary structure of the stem,it can be seen that the water transport ability and drought resistance ability of the Xanthoceras sorbifolia Bunge are strong.The secondary stems were ring-porous wood,and the secondary xylem vessels were mostly multiple pore and pore cluster.Numerous crystalline clusters are present in the cortex and medullary layers.The vessel is a pitted vessel.Wood ray heteromorphic ray,composed of upright ray cell and procumbent ray cell,ray is mainly uniseriate ray.3.Primary roots are divided into epidermis,cortex and stele.The epidermis is composed of a single layer of cells,and the cortex is composed of three layers of cortical parenchyma cells.The cells are closely arranged,and the cortex occupies a large proportion of the roots.The pericycle sheath consists of one layer of cells.There are more ergastic substance in the cortex.The secondary roots were ring-porous wood,the annual rings were obvious,and the vessel were arranged in annual rings along the rings,Large in quantity and large in diameter.4.With the increase of the soil drought stress level,the root vitality of Xanthoceras sorbifolia Bunge seedlings decreased gradually,The content of proline（Pro）,soluble sugar（SS）and malondialdehyde（MDA）gradually increased,and soluble protein（SP）and superoxide dismutase（SOD）,catalase（CAT）,peroxidase（POD）and chlorophyll content first increased and then decreased,leaf photosynthetic parameters net photosynthetic rate（Pn）,stomatal conductance（Gs）,transpiration rate（Tr）and intercellular CO2 concentration（intercellular CO₂concentration,Ci）gradually decreases,In addition,the correlation showed that,chlorophyll content,photosynthetic parameters,SS,SP and MDA were well coupled.After rehydration,Root vitality increased gradually,MDA content decreased gradually,and SOD,CAT and POD activities increased first and then decreased.However,Root vitality,MDA content and CAT activity did not recover to the level of normal control group after 10 days of rehydration.The contents of Pro,SS,SP,chlorophyll,activities of SOD and POD and photosynthetic parameters in leaves recovered to the level of control group at the same period.The results showed that after rehydration treatment,the physiological characteristics of Xanthoceras sorbifolia Bunge seedlings were compensated or overcompensated,which indicated that Xanthoceras sorbifolia Bunge seedlings had strong drought adaptability and self-regulation ability after rehydration.