砧木年龄对锥栗嫁接苗生长及光合特性的影响.

[Objective] Castanea henryi is one of the important woody grains in southern China. The present paper aimed to study the effect of different rootstock ages on the growth and photosynthetic characteristics of grafted seedlings. [Method] C. henryi' Huali 3' was grafted with 2-year-old and 4-year-old rootstocks of Chinquapin, respectively. Then the growth, Pn-PFD response curve and diurnal variation of photosynthesis of the grafted seedlings were measured. [Result] The new shoot length and diameter of seedlings grafted with 4 -year-old rootstock was the highest. The average length of the new shoot of 2 -year group was 92.41 cm, and the average diameter was 11.49 mm. The average length of the new shoot of 4-year group was 131.69 cm, and the average diameter was 14.55 mm. The light saturation point (LSP), apparent quantum efficiency ( AQY), maximum net photosynthetic rate (Pmax), light compensation point (LCP) and dark respiration rate (Rd) of the 4-year-old rootstock grafted plants were all higher than 2-year-old rootstock grafted paints. The diurnal variation curve of Pn of the two groups of rootstock grafted C. henryi new shoots was of double peak type. At 14 :00 pm, there was a valley value, showing a more obvious phenomenon of photosynthetic noon break. When the rootstock was more older, and its the average daily net photosynthetic rate (Pn) was higher than that young rootstock. [Conclusion] The present study indicated that the grafted seedlings with older rootstocks had advantages over growth rate of new shoots, the ability of photosynthesis and light use efficiency. [ABSTRACT FROM AUTHOR]