The Relationship Between The Characteristic Of Branch And Needle In Pinus Massoniana Lamb And Resistance To Hemiberlesia Pitysophila Takagi

Plants against insects is not a passive suffering,but through many types of morphological structures and physiological processes to make a positive response. Because the resistant tree about insects have unique advantages,which in recent years,people take attention to the selection of target pest species resistant. In this paper,branches and pine needles on the measurement of external characteristics,and the paraffin section method and the ultra-thin sectioning were studied to explain the relationship between organizational structure,ultrastructure of needles of the correlation and the pest resistance relations,the following conclusions:1. No victimization,the branch of high resistance family is more than in the mid-resistance and high susceptible family,the main branches and offshoots of the susceptible family are wider than the high resistance family and mid-resistance family,which indicated that the main branch and offshoots are more vulnerable,the diameter is bigger. High susceptible family was significantly longer than the length of needles in the mid-resistance and high resistance family,that needle length was negatively correlated with insect resistance.the bulk density of high resistance family and mid-resistance family was significantly bigger than the high susceptible family,which indicated the greater bulk density,the stronger the resistance. Damage by the pest,the pine needle retention rate in high resistance family and mid-resistance family is higher than high susceptible family. Affected,except for the susceptible family 469 in the main branch and offshoots's diameter smaller than the healthy group, other families is bigger than the healthy group. By pests, the high resistance family 330 and mid-resistance family 155 does not reduce the needle retention,other family down the needle retention rate, indicating the stronger the resistance,the smaller the value of needle retention decreased.2. The organizational structure of needles with different resistant shows that in the unaffected pest damage condition,cuticle thickness,the thickness of the lower epidermis,the epidermis thickness and the thickness of epidermis and cuticle thickness,mesophyll thickness,number and diameter of resin ducts,Victoria tube diameter was positively correlated with resistance to insects, while the epidermal thickness,stomatal density and cortical thickness,has nothing to do with insect resistance. In the damaged plantcompared damaged needle with undamaged needle,the resistance families showed cuticle,lower epidermis,the epidermis and horny and upper epidermis significantly thickened or changed,and susceptible families showed highly significant thinner. None insect needles in the damaged pinus compared to needles in the undamaged pinus,resistance families have thicker cuticle, but high susceptible family has thinner cuticle. None insect needles in the damaged pinus depend on thicking cuticle to increase their resistance..From the microstructure point of view,high resistant family have deposits there in damaged position,Epidermis,mesophyll cells,resin ducts and other organizational structure within the cortex were normal in undamaged position; the mid-resistant family has more epidermal-rupture than resistant, and Mesophyll cell boundaries is not obvious,but within the cortex,vascular structure are normal; and high susceptible family on the epidermal cells and mesophyll cell shape,constriction reduced or broken, resin canal deformation,shrinkage and constricted. At the same time,containing material in inner cortical cells reduced. Epidermal structure,resin ducts,inner cortex,vascular bundles did not significantly changed in different resistant family,but mesophyll cells in high suscept family dramaticly reduced .3. By images from TEM electron microscope,the high resistant family's chloroplast lamellae in damaged needle is not clearer than undamaged needle in the same tree,Golgi increased,a large number of small bubbles formed,and osmiophilic particles appeared. Damaged by the pest,parts of the chloroplast lamellae disappeared,a large number of osmiophilic material appeared,part of the chloroplast envelope is broken in the mid-resistant family,which indicates that mid-resistant family is more seriously broken than the high resistant. High susceptible family chloroplast lamellae disappeared completely,more chloroplast envelope broken,so that light reaction and dark reaction can not be normally carried. At the same time,many starch grains appeared in chloroplast,released into the the cytoplasm;swelling of starch granules may be related to the collapse of the chloroplast membrane. A large number of electron-dense cytoplasm of the emergence of the ball,it may be secrete toxins to destroy the normal metabolism in cells .With undamaged needles in high resistant family damaged plant,chloroplast stroma lamellae and grana lamellae boundaries marked,stacked neatly,mitochondria,cytoplasmic structure of normal,but the chloroplast outer membrane of a small amount of osmiophilic particles existed; part of the starch granules increased and transported out of chloroplasts. In undamaged needles in mid-resistant family damaged plant,chloroplast deformation,lamellar part of the fuzzy,chloroplast envelope surrounded by a large number of osmiophilic particles,which is pathological features. In high susceptible family,the chloroplasts were round or irregular rupture,stroma lamellae and grana lamellae were fuzzy state or disappear into the debris,increased vacuolization; surrounded by the chloroplast starch grain narrow, indicating that high high susceptible family's were unable to carry out photosynthesis.