| Catechins are the main active compounds in tea leaf, which have antioxidant,anti-tumor and other important biological activity. The tea variety processing property,tea organoleptic quality and healthy quality are affected by the content and proportion catechins in fresh leaves of tea plant. In this study, 1236 new tea germplasm (hybrid F1 generation) achieved by mutual hybridization of three high EGCG tea plant strains and one commercial variety were used as research material. The catechins content and genetic performance of these new germplasm and their parents were analyzed. And the net photosynthetic rate, genetic performance and the correlation of the catechins of the new germplasm selected randomly and their parents were studied. The main results are as follows:1.The tea plant new germplasm with high EGCG content were used’ as hybrid parents,and their hybrid technique was studied. The results showed: (1) The artificial hybridization pollination technique of "cutting petals and thrum shown, cutting thrum and emasculation being" used was easy operation and high seed setting rate (an average of 28.28±16.26%, up to 46.34%), and using this technique, the total 1619 tea plants new germplasm of 9 hybrid combinations were acquired, which indicated that the technique overcome the problem of low hybrid seedling rate; (2) Using this technique, tea plant hybrid seed setting rate and plump seed rate were correlated significantly with hybridization combinations, in which plump seed rate and hybridization combinations reached a very significant level; The fruit seed number,seedling rate, hybrid seedlings anthracnose infection rate were not correlated significantly with hybridization combinations.2.The catechins content of hybrid F1 generation were detected. The results showed:(1) The caffeine content was 3.75% averagely, and its coefficient of variation was 19.70%. There were 15 strains whose caffeine content were higher than 6%, and the caffeine content of the strain with highest caffeine content was 6.79%.(2) The total catechins (TC) was 13.81% averagely, and its coefficient of variation was 33.38%. There were 2 strains whose TC content were higher than 27.2%,and the TC content of them was 30.98%, 27.99% ,respectively.(3) The epigallocatechin gallocatechin(EGCG) was 8.57% averagely, and its coefficient of variation was 37.74%. There were 14 strains whose EGCG content were higher than 13%, and the EGCG content of the strain with highest EGCG content was 19.40%.(4) The ester-catechins content and ester-catechins / TC were 10.43%, 75.19%averagely, and their coefficient of variation were 34.98%, 11.11%, respectively. There were 10 strains whose ester- catechins is higher than 19%, and ester-catechins / TC ratio higher than 80%, and the ester-catechins content and ester-catechins / TC of the strains with highest ester-catechins content and ester-catechins / TC were 23.35%,87.72%, respectively.(5) The simple catechins content and simple catechins / TC were 3.38%, 24.81%,averagely, and their coefficient of variation were 46.03%, 33.67%, respectively. There were 4 strains whose simple catechins content higher than 7.40%, and simple catechins / TC ratio higher than 41.96%,and the simple catechins content and simple catechins/ TC of the strains with highest simple catechins content and simple catechins/ TC were 8.70%, 49.34%, respectively.(6) The catechins quality index was 533.11%, averagely. and its coefficient of variation was 72.60%. There were 2 strains whose catechins quality index greater than 1837.36% and EGCG content higher than 15%, and the catechins quality index and EGCG content of them were 4377,27% 17.26 % and 2636.36%, 17.78%, respectively.Among them, the EGCG, ester-catechins and catechins quality index for the strains A2-19, B1-36 are high.3. The genetic performance for catechins of hybrid Fi generation was analyzed.The results showed: (1) The hybrid combination was significant linear correlation with EGC, EC, ECG, simple catechins, ester catechins /TC, simple catechins / TC and the index of catechins, and was significant curve correlation with GA, EGCG, the GCG, ester catechins. TC, EGCG / caffeine and EGCG / TC. (2) The caffeine and TC genetic bias for the different hybrid combinations F1 generation are determined by their parent heritability, while the GA genetic bias is not regularity. (3) The genetic bias of tea plant strains with high EGCG content, high ester-catechins content or high simple-catechins content for the different hybrid combinations F1 generation is biased mainly toward male parent, while the genetic bias of tea plant strains with high catechins quality index is biased mainly toward female parent.4. The tea plant varieties with high EGCG content and their artificial hybridization F1 generation were used as material. The non-linear regression forecast model based on functional networks and generalized linear models were applied. The genetic analysis of tea plant net photosynthetic rate for hybrid combination A3 family was carried out, which indicated that its broad sense heritability, genetic coefficient of variation and expected genetic advance (when select rate is 5%, and k = 2.06) were 0.840,0.0984 and 1.296 μmol/(m2·s) respectively; And 96.43% hybridization F1 generation strains were more than the low parent (female parent), 53.57% more than the parental average, 7.14% ultra high-value parent (male parent), which indicated the genetics was a clear preference for the male parent.5-The correlation between the tea plant fresh leaves catechins and leaf net photosynthetic rate was analyzed. The results showed that: The net photosynthetic rate of tea plant leaves was positive correlation with the EC, GCG content, and negative correlation with C, ECG, EGC, EC, EGCG, simple catechins and total catechins; In particular, the tea leaf net photosynthetic rate shew negative correlation with the ester-catechins and total catechins is significant. So detecting net photosynthetic rate of tea plants could be used as an easy way of early appraisal of the catechins for new tea plant strains. |
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