Low temperature wheat germplasm and its leaf photosynthetic traits and structure characteristics

Low temperature germplasm with constant low plant temperature was found in the nature through a long-time observation on wheat canopy temperature and traits;correspondingly,high temperature germplasm with constant high plant temperature also exists. Compared with the high temperature germplasm,the chlorophyll content and the net photosynthetic rate of the three functional leaves on the top of the low temperature wheat germplasm are higher and the structure tends to be more complicated,which is characterized by smaller mesophyll cells and more closely arranged cell layers,more and denser chloroplasts with thick stroma, more granas and well developed grana lamellae,a larger vascular bundle area with smaller interspace. All these characteristics embody the consistency of structure and function and provide the theoretical bases for looking for and cultivating the new low temperature materials in agricultural practice.