摘要
【目的】研究授不同花粉的山核桃果实发育期间外果皮光合速率、光合色素及叶绿素荧光特性的变化,探讨花粉授粉对山核桃外果皮光合特性的影响,以及其与果实干物质形成的关系,初步揭示花粉直感使山核桃果实增大的光合生理机制,为探寻进一步提高山核桃产量的技术路径提供参考依据。【方法】设置2种授粉组合[山核桃×山核桃(hp)和山核桃×薄壳山核桃(pp)],于授粉后不同天数测定2种花粉授粉山核桃果实的光合面积、干质量、光合速率、光合色素及叶绿素荧光特性的变化。【结果】1)薄壳山核桃花粉(pp)授粉的山核桃果实显著大于山核桃花粉(hp)授粉的果实,且外果皮颜色更绿。果实发育前期(授粉后50~73天)和后期(授粉后103~120天),pp授粉果实表面积和干质量的日增量均显著高于hp授粉果实。授粉后50~85天,pp授粉果实的光合速率显著高于hp果实。2种花粉授粉山核桃果实的干质量日均增量与其单果的光合速率日均增量之间呈显著相关。2)果实发育过程中,pp授粉果实的叶绿素含量显著高于hp果实,且果实的叶绿素含量与其外果皮的光合速率呈显著相关。3)在一定光强(1 265μmol·m^(-2)s^(-1))下,pp授粉果实的实际光化学效率(Y)、表观电子传递速率(ETR)和光化学猝灭系数(qP)均显著高于hp授粉果实。果实发育过程中,hp授粉果实外果皮ETR达到峰值的光强强度显著低于pp授粉果实外果皮ETR达到峰值的光强强度,且在果实发育后期(授粉后103~120天),hp授粉果实外果皮ETR达到峰值的光强强度显著降低,下降幅度约为50%。在果实发育后期(授粉后103~120天),hp授粉果实外果皮的Y(NO)显著增加,pp授粉果实外果皮的Y(NO)无明显变化;且在授粉后120天,与hp授粉果实外果皮相比,pp授粉果实外果皮具有较高的Y(Ⅱ)和较低的Y(NO)。【结论】授粉后50~73天,pp授粉的山核桃果实干质量快速增加主要是由于其较大的光合面积和较高的光合速率;授粉后103~120天,pp授粉果实干质量快速增加主要是由于其较大的光合面积。果实发育后期(授粉后103~120天),hp授粉的果实较易受到光损伤,而pp授粉的果实具有较强的抗光抑制能力,这可能是pp授粉果实生物量增加的重要原因。
【Objective】To elucidate the effect of metaxenia on photosynthesis that promotes fruit enlargement in Carya cathayensis,the shape,gas exchange,chlorophyll content and chlorophyll fluorescence characteristics of C.cathayensis fruits pollinated with two different pollens during the fruit growth stages were measured.【Method 】 Two pollination combinations(C.cathayensis × C.cathayensis or C.cathayensis × C.illinoensis) were conducted in this study.The dynamic changes in photosynthetic area,dry mass,photosynthetic rate,chlorophyll content and chlorophyll fluorescence were investigated during the fruit growth stages.【Result】1) The hickory fruits pollinated with pecan pollens(pp) weresignificant larger and greener than those pollinated with hickory pollens(hp).Compared with the hickory fruits pollinated with hp,the increasing rate of the surface area and dry mass per day per fruit was significant higher in hickory fruits pollinated with pp at the early and late fruit growth stages(from 50 to 73 d after pollination and from 103 to 120 d after pollination).The photosynthetic rate per area of exocarp in hickory fruits pollinated with pp was significantly higher than that in fruits pollinated with hp during 50 to 85 days after pollination.Moreover,a significant positive correlation was found between the dry mass increment and photosynthesis rate increment expressed on per fruit per day of hickory fruits.2) The chlorophyll content of exocarp in fruits pollinated with pp was significantly higher than that in fruits pollinated with hp,and there was a significant positive correlation between the chlorophyll content and photosynthetic rate of exocarp in hickory fruits.3) The Y,ETR and qPin fruits pollinated with pp were significantly higher than those in fruits pollinated with hp at PAR of 1 265 μmol·m^-2s^-1.The light intensity of the maximum ETR in exocarp of hickory fruits pollinated with hp was significantly lower compared with that in fruits pollinated with pp during the fruit growth stages.The light intensity of the maximum ETR in exocarp of hickory fruits pollinated with hp significantly decreased at the late fruit growth stage(from 103 to 120 d after pollination),decreased by about 50%.The Y(NO) in exocarp of hickory fruits pollinated with hp significantly increased from 103 to 120 d after pollination.Compared with pericarp of hickory fruits pollinated with hp,the exocarp of fruits pollinated with pp had higher Y(II) and lower Y(NO).【Conclusion】At the early fruit growth stage(from 50 to 73 d after pollination),the faster increase in dry mass of the fruits pollinated with pp was due to the higher photosynthetic surface area and photosynthetic rate;at the late fruit growth stage(from 103 to 120 d after pollination),the faster increase in dry mass of the fruits pollinated with pp was due to the increased photosynthetic surface area.At the late fruit growth stage(from 103 to 120 d after pollination),the fruits pollinated with hp was more susceptible to light damage.It is suggested that the higher dry mass of fruits pollinated with pp might to related to the adaptability of high-light at the late growth stages.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2017年第1期38-46,共9页
Scientia Silvae Sinicae
基金
浙江省自然科学基金项目(LY15C160003)
国家重大科学研究计划863计划(2013AA102605)
浙江省大学生科技创新活动计划资助项目(2015R412044)
浙江省林学重之重一级学科研究生创新项目(201502)
杭州市科技发展计划(20130432B85)
关键词
山核桃
外果皮
气体交换参数
叶绿素荧光
物质生产
hickory
exocarp
gas exchange parameters
chlorophyll fluorescence
biomass production