Study On Cold Resistance Of Some Bamboo Species

Bamboo(Poaceae ,Bambusoideae)is a class of evergreen plant,which is extremely important renewable forest resources and landscape plants.There are more than 70 genera and 1200 species in the world. China is one of the bamboo's center and the most important country in the world,there are 37 genera and more than 500 species of bamboo in china.Most of them have good viewing value.They are green in every season,have graceful posture, high cultural taste and aesthetic characteristics of landscape. Since ancient times, they have been very favorite gardening materials,and widely used in modern bamboo park, as well as the green channel and public green space.Bamboo distribution has clear zone and regional characteristic due to climate affecting,its cultivation area concentrates in the south of china,which including four major areas. Fujian,Jiangxi,Zhejiang,Hunan Province.Although has been carried a large-scale bamboo introduction work in the 1950s,1960s, it had caused some strong resistances bamboo to introduce to the north of the Yellow River,the bamboo introduction work obtained great success. but temperature is the main limit factor of cannot obtaining further promoted application in the north of the Yellow River of China landscape.It researches cold resistance of different types (varieties) from morphological, physiological aspects through introduction and cultivation management ,which takes low temperature as mainly factor.The main conclusions are as follows:1.Leaf freezing damage is an important indication of bamboo's freezing damage,it reflects the extent of branche's damage. During the winter,the cold resistant of 29 kinds of bamboos is difference,leaf blade's freeze injury condition is also respectively difference in the different low temperature.2. The cold resistance of bamboo in the experiment is divided into 3 types according to frost damage of bamboo stems and leaves in winter and spring :The first category:Cold resistance is strong .They can survive safely in winter without taking cold security measures, and can grow new sprout in next year. Growing trend is well.For example, P.glauca,P.bambusoides,P. iridescens,P.aureosulcata,P.aureosulcata f. aureocaulis,P. vivax f. aureocaulis,P. vivax,P.bambusoides f.shouzhu,P.aureosulcata f.spectabilis,P.rubicunda,P.varioauriculata,Ps. japonica.The second category: Cold resistance is middle.Bamboo leaves start to chlorosis, some dead. It also can grow new sprout in the second year and can be applied to local landscape. For example,P.bissetii,P. nidularia,P. nigra,P.praecox cv. Prevernalis,In.latifolius,Hi. tranguillans f.shiroshima,B. fargesii.The third category: Cold resistance is bad. Most bamboo leaves froze to death during the winter, the freeze injury is serious,For example,P.bambusoides f.lacrima-deae,P.prominens,P.glauca f.yunzhu,P.angusta,P. aurea,Pl.chino f.hisauchii,Pl.oleosus,S.fortunei,S.argenteastriatus,P.heterocycla cv.Pubescens.Particularly P.bambusoides f.lacrima-deae,P.heterocycla cv. Pubescens and Pl. oleosus's leaves all freeze to death. P. heterocycla cv. Pubescens freezes to death completely, and has not sent bamboo shoots to produce hsinchu.3. The change of REC under low temperature stress compares the law. The relative conductivity were increased with chilling stress strengthened which increased cell membrance permeance.The changes of REC showed slowly-fast-slowly and changing curves showed'S'modle.4.The LT50 according to the logistic equation,the LT50 of P. aureosulcata,P. aureosulcata f. aureocaulis,P. bambusoides,P. bambusoides f.lacrima-deae,P.bissetii,P. bambusoides f.shouzhu,P. glauca,P.rubicunda is -20.24℃,-26.24℃,-16.89℃,-14.67℃,-15.99℃,-16.32℃,-23.03℃and -19.16℃.The results of LT50 showed that the cold resistance sequence of the eight varieties is:P.aureosulcata f. aureocaulis> P. glauca>P.aureosulcata>P.rubicunda>P. bambusoides>P.bambusoides f.shouzhu>P. bissetii>P.bambusoides f.lacrimadeae .5.The result of ANOVA showed that REC and POD was different under different low-temperature treatment, SOD activity, soluble protein content, soluble sugar content, MDA content, chlorophyll total content under different low-temperature treatment and proline content of different variety were highly significant differences.SOD activity, total chlorophyll content of different variety,different low temperature difference between free proline content significantly;between different species MDA content, soluble protein content, soluble sugar content were no significant differences.6.Using the methods of subordination and counter-subordination function,we can get a comprehensive assessment of cold resistance ,the cold resistance order is P.glauca< P.aureosulcata f. aureocaulis>P.rubicunda>P. aureosulcata>P. bambusoides> P. bissetii > P.bambusoidesf.shouzhu > P. bambusoides f.lacrima-deae.