不同砧木对砂糖橘生长势、光合作用和碳水化合物含量的影响

Effects of Rootstocks on Tree Growth,Photosynthesis and Carbohy-drate Content of‘Shatangju’Tangerine

本研究探索不同砧木对砂糖橘的生长、光合性能和碳水化合物含量的影响,从而筛选出适合砂糖橘栽培的最适砧木。测定嫁接在2年生宜昌橙、枳壳、砂糖橘、香橙和粗柠檬砧上的砂糖橘的生长势、叶绿素含量、光合性能[净光合速率(net photosynthesis,P_(n))、蒸腾速率(transpiration rate,T_(r))、气孔导度(stomatal conductance,G_(s))、胞间CO_(2)浓度(intercellular CO_(2)concentration,C_(i))]和碳水化合物含量等。结果表明:以宜昌橙为砧木的嫁接亲和性最差,砧穗粗度比值为2.08,嫁接苗生长势最弱,而以粗柠檬和香橙为砧木的砂糖橘生长势最强;不同砧木砂糖橘叶片中总叶绿素含量由高到低依次为:枳壳砧>粗柠檬砧>香橙砧>本砧>宜昌橙砧,其中,除了枳壳砧和粗柠檬砧的砂糖橘叶片中总叶绿素含量之间无显著差异外,其余砧穗组合之间均差异显著;香橙砧的P_(n)和G_(s)均显著大于宜昌橙砧;香橙砧和粗柠檬砧砂糖橘叶片中的可溶性总糖、还原糖和蔗糖均显著高于宜昌橙砧。由此可知,宜昌橙砧砂糖橘光合效率较低,树体生长势较弱,而嫁接在香橙砧上的砂糖橘则树势健壮、光合性能较强,可推荐为砂糖橘的优良备选砧木,进一步研究其品质、产量、抗病虫性和抗逆性能等。

The object of this study was to investigate the growth,photosynthesis and carbohydrate of‘Shatangju’man-darin grafted on various rootstocks.The tree vigor,net photosynthesis(P_(n)),transpiration rate(T_(r)),stomatal conductance(G_(s)),intercellular CO_(2)concentration(C_(i)),leaf chlorophyll,carbohydrates of‘Shatangju’mandarin budded on Ichang papeda(Citrus ichangensis Swingle),Trifoliate orange[P.trifoliate(L.)Raf.],‘Shatangju’mandarin(C.reticulata Blanco cv.Shatangju),Fragrant orange(C.junos Sieb.ex Tanaka),Rough lemon(C.jambhiri Lush)were evaluated.The scion height,trunk cross-section area(TCSA),leaf area and shoot length of‘Shatangju’on Fragrant orange and Rough lemon were significantly bigger than that on the Ichang papeda.The lowest affinity was found with Ichang papeda,which showed the highest rootstock/scion ratio(2.08).Total leaf chlorophyll content range from 0.85 mg/g FW to 1.40 mg/g FW,significantly higher leaf chlorophyll content was found in trees grafted on Rough lemon and Trifoliate orange than other grafting combinations.Trees on Fragrant orange had the highest net photosynthesis(P_(n)),transpiration rate(T_(r)),stomatal conductance(G_(s)),while Ichang papeda induced the lowest photosynthesis rates.As the production of CO_(2)photosynthesis,high photosynthesis efficiency led to higher carbohydrate(total soluble sugar,sucrose,reduced sugar content)in‘Shangtangju’leaves budded onto Fragrant orange and Rough lemon rootstocks compared to trees on the Ichang papeda.The data confirmed that the low affinity of Ichang papeda rootstock and‘Shatangju’mandarin scion combination caused the lower photosynthesis efficiency and tree vegetative growth.The Fragrant orange rootstock could be a suitable candidate for the‘Shangtangju’mandarin production in citriculture.