Study On Anatomical Characteristics Of Dwarf Chinese Fir And Cloning Of CCR And CesA1 From Chinese Fir

Cunninghamia lanceolata is an important timber species endemic in China, and accounts for a considerable position in the forestry industry, It is significant in breeding on the cedar wood and wood-related genetic research in Chinese fir. Our laboratory obtained a dwarf characteristics of fir material, the study found some of its normal fir wood indicators are quite different, in order to reveal the reasons for fir dwarf, this experiment use the material of dwarf and normal fir, study the anatomy of dwarf fir, fir dwarf to clarify the basis of anatomy and physiology; Study on anatomical characteristics of dwarf Cunninghamia lanceolata The results are as followed:â‘ Dwarf Cunninghamia lanceolata growth ring is distinct and the early wood changed slowly into the late wood. The bordered pits on tracheid walls are uniseriate. Axial parenchyma is large and star bulk array. Xylem rays are mostly uniseriate with 3¹2 (3⁷)cells in height. The cross-fields are predom inantly taxodiod with 2⁴ pits.â‘¡The average values of the dwarf Chinese fir tracheid density and radial division layer are 4 047 pieces.mm^-2 and 118 layers.ring^-1 in second annual ring.â‘¢The average values of dwarf Cunninghamia lanceolata tracheid length ,width, wall thickness , ratio of wall thickness to cavity, length to width and cavity to width are 1560.5μm, 20.06μm, 3.602μm, 0.21, 69.90 and 0.830 respectively.Lignin, cellulose synthesis is an important reasons for the impact of forest timber, to reveal the cedar wood and genetic mechanism of the formation of lignin, cellulose synthesis related genes is an important aspect.In this study, A full-length cDNA clone encoding CCR was isolated from the cDNA prepared from xylem zone of Cunninghmai Lancoealat by the RT-PCR and 5', 3'RACE methods. The cDNA is 1,379 bp in length with an open reading frame(ORF)which is capable of encoding a protein of 324 amino acids,with a predicted molecular mass of 35.71 kDa.The deduced a sequence of the ORF showed 87% identity with CCR from other known plants. The phyloenetic tree of CCR showed it has a close relation with Picea abies.Tissue specific expression test revealed that there were significant differences in roots,stems,leaves and seedlings.The expression of CCR in root was the highest. But In the dwarf fir, CCR gene expression in only normal fir 1 / 5 1/ 4. These results show that the fir and cedar lignification CCR gene may have more direct relationship. Use the same method cellulose synthase CesA gene was cloned, we get a length of 3235bp cDNA nucleotide sequence, named CesA1, the sequence contains 2,976bp open reading frame (ORF), the putative gene encoding fir CesA 1,991 amino acid sequence on the NCBI Blast comparison, the results show: the CesA1 amino acid sequence and a database of other plant CesA amino acid sequences are highly similar, with the known Pinaceae Loblolly Pine (Pinus taeda, AAX18647.1) cellulose synthase CesA gene amino acid sequence similarity of the highest, reaching 81%; The phylogenetic tree showed that: fir and loblolly pine CesA amino acid sequence (Pinus taeda) amino acid sequences clustered together, indicating the same as the loose plants of Chinese fir and loblolly pine in evolution are close relatives.These two genes and their expression characteristics will providing some theoretical and experimental basis on the formation of fir genetic mechanism.