The Comparative Anatomical Observation Of The Cucumber D0462 And 129

Cucumber (Cucumis sativus L.) is a major vegetable crop worldwide and one of China major vegetable crops which have a huge cultivating area as well as a wide range of planting areas. The cucumber is a vine plant plus planting it needs a large area and putup, so the plant density is reduced and the production is affected to a certain extent. Dwarf are good resources of breeding dwarf melons. By taking advantage of these resources, we can breed varieties suitable for mechanized operations, increase planting density and improve production efficiency. This study made a comparative anatomy of vegetative organs of cucumber dwarf varieties and vine varieties, aiming to discuss the growth development morphology and anatomic characteristics of cucumber dwarf. Meanwhile this study revealed the dwarfing mechanism of cucumber and provided a theoretical basis for condensed planting of cucumber with high production.The results of the experiments are shown below:1. The seed size, weight per 100particles, plant height, hypocotyl length, diameter of main stem, internode number, internode length, petiole length of dwarf varieties D0462 are significantly smaller than 129 varieties.2. The primary roots of cucumber are three prototypes. The diameter of primary root of dwarf varieties D0462 is significantly longer than of 129 varieties, as well as the epidermal thickness, cortical thickness and vascular cylinder diameter. The secondary roots of cucumber are underdeveloped. The phloem and xylem thickness of dwarf varieties D0462 is significantly higher than 129 varieties, as well as the capability of transferring water.3. The hypocotyl growth rate of dwarf D0462 is always smaller than 129 varieties and the hypocotyls epidermal cells'width of 129 is obviously larger than of D0462. So we can see that the shortness of dwarf's hypocotyl is due to the small width of the hypocotyls epidermal cells. The number of D0462's vascular is slightly lower than 129 in all periods; in early growth stage, the D0462 vascular catheter was significantly higher than the number of 129 species, but around the 50d the number of 129's vascular bundles is slightly over the number of D0462. The large diameter and small diameter of 129's catheter tube grow with days, increasing from less than to more than D0462 in 20 days,4. The number of cotyledons of dwarf varieties D0462 is same with the 129; the horizontal length of epidermal cells of D0462 is smaller than 129 varieties and the vertical length epidermal cells of D0462 and 129 varieties are almost equal. The number of parenchyma cells per unit area of D0462 is smaller than 129 varieties. In the whole growth period, the leaf thickness of dwarf varieties D0462 keeps increasing, but when it's fully developed the leaf thickness reduces; the palisade tissue gradually increases and the thickness of spongy tissue, the number of vascular reduces when it's fully developed.5. Compared to normal varieties, the anatomy of dwarf D0462's stem has no significant change. The diameter of stem's phloem cells, vascular mesh and number of pipes of dwarf varieties D0462 are smaller than 129 varieties, but the difference is not significant. As we can see from the longitudinal section of stem, the lateral length of epidermal cells and parenchyma cells of D0462 is less than 129 varieties, but the number of parenchyma cells per unit area of D0462 is smaller than 129 varieties.6. In the same growth period, the leaf blade thickness, epidermal thickness, palisade tissue and spongy tissue thickness of dwarf D0462 were significantly greater than 129 varieties. By the observation under scanning electron microscopy, the epidermal cells of dwarf varieties D0462 is fewer than 129 varieties; no significant difference of trichome density between the two species; stomatal density of D0462 is smaller than 129 varieties; stomatal aperture of dwarf D0462 is greater than 129 varieties.7. The petiole length of cucumber can keep on growing for 60 days. The surface area of parenchyma cells of dwarf D0462 is larger than 129 varieties, but fewer in vascular bundles...