The effect of preharvest calcium sprays and low temperature treatment on storage quality of Yangshuo kumquat fruits with preharvest calcium sprays three times and then storage at 4 and 25 ℃ when the fruits were mature were studied.The results showed that the rotten rate and weight loss rate,the fruit firmness,TSS,TA,TS and Vc content of kumquat fruits treated by CaCl2 and 4 ℃ low temperature storage for 60 days were 30.00 %(absolute value)and 3.98 %(absolute value) lower,38.48 %,2.50 %(absolute value),0.11 %(absolute value),4.58 %(absolute value)and 52.56 % higher than that stored at 25 ℃ for 60 days without calcium spray,respectively.The preharvest calcium sprays or low temperature storage could restrain the occurrence of rotten and weight loss,delay the decrease of the fruit firmness,TSS,TA,TS and Vc content,combination of both was the best treatment in maintaining the quality of kumquat fruits.

The dynamic changes of the Yangshuo kumquat fruits qualities were compared under rain shelter cultivation covered with plastic film and in open field cultivation as control from December 20,2010 to April 15,2011.In order to understand the effects of rain shelter cultivation on quality of Yangshuo kumquat(Fortunella crassifolia Swingle cv.Yangshuo) fruits on tree storage in Yangshuo county.The results showed that the storage period on tree of Yangshuo kumquat under rain shelter cultivation could extend to mid-April of the next year and the good fruit rate still could reach 98.9%.The rain shelter cultivation could not noly delay the decrease of the fruit firmness and maintain higher VC content of later period,but also increased its soluble solids content,TSS-TA ratio and TS-TA ratio.During the whole storage period on the tree,the fruit firmness under rain shelter cultivation was 10.08% to 14.26% higher than that in open field cultivation,its soluble solids content was 2.12% to 5.86% higher than the control;titratable acid content was 13.64% to 14.29% lower than the control;soluble sugar content,TSS-TA ratio and TS-TA ratio of fruit under rain shelter cultivation were all higher than that of control.The VC content of kumquat fruits on the tree storage increased during the first two months and reached maximum in the second month,then reduced rapidly,but the VC content of kumquat fruits under rain shelter cultivation was 8.69% to 14.73% higher than that of control.

A pair of primers with 18 bp in length were designed according to a conserved sequence of the homologous gene of different plant species FLOWERING LOCUS T(FT).Taking the genomic DNA of Carya cathayensis as template,a 152 bp long DNA fragment was amplified by polymerase chain reaction(PCR),And the fragment was cloned into a pMD19-T vector and then sequenced.The sequence analysis indicated that the deduced amino acid sequence of the fragment was part intron of the forth exon in the fragment with FT homologous genes encoding 50 amino acids,which was registered in GenBank with the accession number FJ858260.1.The homology test result showed that the deduced amino acid sequence of the fragment was 88%-96% homologous genes with FLOWERING LOCUS T(FT) of other plant species.