柑橘黄龙病菌浓度对琼中绿橙果实品质的影响

为了定量衡量黄龙病菌量对琼中绿橙果实品质的影响，本实验以采自海南琼中橘园中感染了柑橘黄龙病的琼中绿橙为实验材料，用实时荧光定量PCR相对定量的方法测定果实中柑橘黄龙病菌的浓度，同时对果实品质的8个外在指标（果实纵经、横径、果形指数、单果重、果皮率、残渣率、种子数量、种子重量）和5个内在指标（果汁率、可食率、可溶性固形物含量、可滴定酸含量、固酸比）进行测定，研究黄龙病菌浓度对琼中绿橙果实品质的影响。结果表明：随着琼中绿橙果实中柑橘黄龙病菌浓度的增大，果实外观品质变化明显的指标包括果实纵经、果形指数、单果重（p<0.05），其中果实纵经呈现明显下降趋势，从64.97mm下降到57.44mm，相对较少11.59%；果形指数呈现明显上升趋势，从0.83上升到0.94，相对增多13.25%；单果重呈现下降趋势，从166.35g下降到109.66g，相对较少34.08%；果实横径、果皮率、残渣率、种子数量、种子重量等指标变化不明显。随着琼中绿橙果实中柑橘黄龙病菌浓度的增大，果实内在品质变化明显的指标为可溶性固形物含量，可溶性固形物含量呈现明显下降趋势（P<0.05），从9.65%下降到8.19%，相对减少15.13%；果汁率、可食率、可滴定酸含量和TSS/TA没有明显变化。结论：在黄龙病菌浓度增加的情况下，琼中绿橙在果实外观、内在品质等多个指标呈现下降趋势。研究结果为定量评价黄龙病对柑橘果实的影响提供参考。

Effect of Citrus Huanglongbing Bacteria Concentration on Quality of Qiongzhong Green Orange

In order to quantitatively measure the effect of the amount of Huanglongbing on the quality of Qiongzhong green orange , this experiment used Qiongzhong green orange, which was infected with Huanglongbing in the orange orchard of Qiongzhong in Hai-nan, as the experimental material.It used the method of real-time fluorescence quantitative PCR relative quantitative measure-ment to determine the concentration of citrus Huanglongbing bacteria in the fruit, and at the same time 8 external indicators of fruit quality ( longitudinal diameter, transverse diameter, fruit-shaped index, fruit weight, peel rate, residue rate, seed quantity, seed weight) and 5 inland indicators (juice rate, eatability rate,soluble solids content,the content of titratable,TSS/TA) were meas-ured to study the effect of the concentration of bacteria on the quality of Qiongzhong green orange fruit. The results showed that with the increase of the concentration of citrus bacteria in the green orange fruit, the indicators of obvious changes in the appear-ance quality of fruit included fruit longitudinal diameter,fruit-shaped index and single-fruit weight. Fruit included fruit longitudinal diameter showed a clear downward trend,from 64.97mm to 57.44mm,a relative decrease of 11.59%; Fruit-shaped index average showed a clear upward trend, from 0.83 to 0.94, a relative increase of 13.25%;Trend, the average weight of a single fruit de-creased from 166.35g to 109.66g, a relative decrease of 34.08%; Transverse diameter, fruit skin rate, residue rate, the number of seeds and the weight of seeds did not change significantly. With the increase of the concentration of citrus bacteria , the fruit inland indicators are the obvious index of quality change including soluble solid content, where the soluble solid content showed a significant downward trend (P<0.05), from 9.65% to 8.19%, a relative decrease of 15.13 %; The rate of juice, edible rate, the con-tent of titratable and TSS/TA did not chang significantly. To sum up, in the case of the increase in the concentration of bacteria, the Qiongzhong green orange showed a downward trend in many areas of fruit appearance and innate quality. The results provide reference for quantitative evaluation of the effects of Huanglongbing disease on citrus fruits.