Mechanism Of Drought Resistance And The Bamboo Shoots Law Of Special Bamboo In Fujian Province

Regional unique bamboo resources as an important part of ecological system, plays an irreplaceable role for the stability and sustainable development of the environment. This paper conducts the research to the special bamboo species of Fujian province—— [Acidosasa longiligula (Wen) Chao et Chu], [Acidosasachienouensis (Wen.) C. C. Chao. et Wen], [Brachyst achyum densiflorum (Rendle) Keng], [Acidosasa edulis Wen],[P.sanmingensis S.L.Chen et GY.Sheng] and [Bambusa ventricosa McClure].Research content including the biological characteristics, the bamboo species of drought resistance mechanism and regularity of shooting etc.. These results will provide scientific theoretical basis for the protection o bamboo resources in Fujian province. The main conclusions as follows:(1)They are the special bamboo in Fujian province.The several bamboo species mainly distributed in Fujian province in the northwest and northeast, especially concentrated in Low mountain and hill area of Sanming and Nanping. The geographical position is 25.70°N～27.77°N,117.17°E～118.46°E.(2)[P.sanmingensis S.L.Chen et G.Y.Sheng] and [Brachystachyum densiflorum (Rendle) Keng] with smaller diameter below 3cm,the height of adult bamboo is 3-4m; [Acidosasa longiligula (Wen) Chao et Chu], [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen], [Acidosasa edulis Wen], [Bambusa ventricosa McClure] with pale green bamboo sheet and bamboo short spike,other bamboo species is dark green. Shooting period is mainly at the end of 3 months to 5 months early, for more than a month to one and a half months, the longest shooting period of [Acidosasa longiligula (Wen) Chao et Chu] is up to two months.(3) 6 bamboo species under drought stress, its leaf water content and chlorophyll content showed varying degrees of decline. Drought stress is less than 6%, the content of chlorophyll and leaf water content decreased significantly; the water content in leaves of an average decline of 15%, [P.sanmingensis S.LChen et GY.Sheng] of the water content of the leaves showed a relatively stable, has been maintained at 58%～62%; the study found that the chlorophyll content of 8%～10% did not change significantly and appear decreased below 6%,it is decline in 33%～45%,the content of chlorophyll of [Brachystachyum densiflorum (Rendle) Keng] has been maintained at the level of under 4mg/g.(4)The free proline content under drought stress, the content appears to increase. The proline content of [Bambusa ventricosa McClure] and [Brachystachyum densiflorum (Rendle) Keng] does not increase below 8%;between 8%-20%, the free proline content did not change significantly of difference bamboo species;below 8%, the free proline content significantly increased.Soluble sugar content changes of [Bambusa ventricosa McClure] showed a "rise-drop-rise "; the soluble sugar content of [Acidosasa longiligula (Wen) Chao et Chu] stabled stay on 0.48-0.63mg/g level; the soluble sugar content of [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen] will be obviously increased when the drought stress below 6%;the soluble protein content of 6 bamboo species show upward trend; the content of soluble protein of [Brachystachyum densiflorum (Rendle) Keng]decreased in 8% and 4%;the content of soluble protein of [Acidosasa edulis Wen] in 5.3～6.4mg/g; the difference between[Acidosasa longiligula (Wen) Chao et Chu], [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen], [Brachystachyum densiflorum (Rendle) Keng] and [Bambusa ventricosa McClure] is significant; the differences between the [P.sanmingensis S.L.Chen et G.Y.Sheng] and [Acidosasa edulis Wen] significantly.(5)Under drought stress, cell membrane permeability increase.Specific performance is electrical conductivity and MDA content increase, the conductivity of [Bambusa ventricosa McClure] increased most significantly, increased to 122.5%,compared with CK; [Acidosasa longiligula (Wen) Chao et Chu] and [Acidosasa edulis] increased steadily under drought stress at a speed of 10%;the conductivity levels of [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen] rose slowly before 4%, decline in 2%; the content of MDA do not change significantly between 8%～20%, after that the content of rapidly rising;MDA content of [Bambusa ventricosa McClure] and [Acidosasa edulis Wen] increased by 4 times, other species change more than 80%. Multiple comparison analysis showed that, permeability of cell membrane in the difference among varieties was not significant, the differences between different treatments of drought stress significantly.(6) The SOD activity of [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen], [Brachystachyum densiflorum (Rendle) Keng],[Bambusa ventricosa McClure] first increased and then decreased; the SOD activity of [Acidosasa longiligula (Wen) Chao et Chu]and [P.sanmingensis S.L.Chen et G.Y.Sheng] turns up, the maximum is 630U/g;the SOD activity of [Acidosasa edulis Wen] maintain the stable degree under 6% stress. The CAT activity peak of [Acidosasa edulis Wen] and [Brachystachyum densiflorum (Rendle) Keng] appear in the level of 8%, the CAT activity of [Acidosasa longiligula (Wen) Chao et Chu ]can be up to 800U/g; multiple comparisons analysis showed that CAT activity showed a positive correlation with the variety and soil water content. POD activity changed little, the POD activity of [Brachystachyum densiflorum (Rendle) Keng] and [Acidosasa edulis Wen] has remained below 800U/g; the POD activity of [Bambusa ventricosa McClure] under severe stress (10%) shot up 1.7 times, the activity of POD is not suitable as a reference indexevaluation of plant drought resistance ability.(7)Using DPS software to principal component analysis of 10 physiological indexes, the results showed that:MDA, conductivity, soluble protein and chlorophyll content can be used as a key indicator of plant drought resistance ability, its contribution to the bamboo species drought resistance is 42.97%,24.87%,20.54% and 11.62%.(8)Using the membership function method, and reference of 7 physiological indexes for the comprehensive evaluation of drought resistance of 6 species of bamboo, The results show that [Bambusa ventricosa McClure] is the most drought resistant, its D is 0.805;then is [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen], [P.sanmingensis S.L.Chen et GY.Sheng] and [Acidosasa edulis Wen] obtained 0.203 and 0.332, the worst resistance to drought stress. Be based on the best drought resistance, the [Bambusa ventricosa McClure] showed strongly environment adaptiveness and widely cultivated; [P.sanmingensis S.L.Chen et G.Y.Sheng], the ability of [Acidosasa edulis Wen] and [Brachystachyum densiflorum (Rendle) Keng] to adapt to the new environment is weak.(9) The species bamboo shoot period has been extended from the mid of March to the latter of May. The bamboo rate is low, the rate are 39.39%,48.98%,14.46%,40.23%,66.67%,70%;the highly bamboo rate appear in the end of shooting period. The highly degenerated shoot concentrated on initial and mid of shooting stage. Young shoots grow rapidly, the bamboo shoots of [Acidosasa edulis Wen], [Acidosasa longiligula (Wen) Chao et Chu] and [Acidosasa chienouensis (Wen.) C. C. Chao. et Wen] can grow exceed lm in bamboo medium-term of one day, shoot apical merited and in bamboo shoot meristem capability is extremely strong, rapid growth, that can become a bamboo in the same year.(10)Bamboo shoot back occurred at the beginning of the shooting period, the shoot back of [P.sanmingensis S.L.Chen et GY.Sheng] throughout the entire shoot stage. The main reasons of shoot back are inadequate nutrient and pest,such ratio of shoot back is:70.42%,66.67%,67.3%,60%,68.75%, and 66.67%. One reasons of degraded shoot of [Acidosasa edulis Wen] is artificial robbing,it is accounted for up to about 25%, the highest in six kinds of bamboo species,it is mainly because the bamboo shoots of [Acidosasa edulis Wen] taste delicious and hidden highly nutritional value. The height of shoot back is below 45cm, the shoot back of [Bambusa ventricosa McClure] highly concentrated above 60cm, the proportion reached 66.67%;the height of shoot back of [Brachystachyum densiflorum (Rendle) Keng] below 30cm, [Acidosasa longiligula (Wen) Chao et Chu] with the highest rate of shoot back.(11)The growth regularity of the bamboo shoots are highly meet logical Teece growth curve, Logistic through the nonlinear regression analysis, obtained the bamboo shoots growth equations of bamboo species. The fitting coefficients are:0.991,0.997,0.997,0.999,0.998, and 0.997. the fitting effect is good. Young shoots growth show "S" type that is mean bamboo shoots growth follows the trend" slow-fast-slow".