| P.decomposita is a rare wild germplasm resource unique to China,with unique leaf shape,rich and diverse flower colors,roots that can be used as medicine and seeds that can be extracted into oil.It plays a huge role in ornamental,medicinal,oil,edible and cultural aspects,with high economic value and development and utilization potential.In this study,P.decomposita seeds was taken as the research object,aiming to achieve rapid and efficient breeding of P.decomposita and select excellent provenances.In terms of some problems such as endangered mechanism,breeding work,genetic variation,selection of improved variety,resource protection and garden promotion,the single factor analysis of variance,two-factor analysis of variance,Person correlation analysis,system cluster analysis,principal component analysis and multiple comparative analysis methods were used,and a comprehensive and systematic survey of the distribution area of the group and a seed quality analysis were carried out,so as to provide a reasonable and effective theoretical basis and technical means for the selection of excellent provenance,seedling propagation,resource development and utilization,and large-scale garden cultivation of P.decomposita.The main research results are as follows:?1?Through the study on the seed quality difference of P.decomposita from different provenances,it was found that in addition to the length-width ratio of seed and the thickness of seed coat,the differences in seed length,seed width,seed purity,1000-grain weight seed viability,seed vigor and seed moisture content among different provenances were significant.The results of variation analysis showed that in terms of seed morphology,the variation coefficient of seed coat thickness is the largest in both intraprovenance and interprovenance variation?>10%?and the variation coefficient of seed width was the smallest?<10%?;in terms of seed quality,the variation coefficient of seed vigor and seed viability was larger?>10%?,which was greatly influenced by environmental factors;the variation coefficient of seed purity,1000-grain weight and seed moisture content was smaller?<10%?,which were less affected by environmental factors.?2?The correlation analysis of seed quality of P.decomposita from different provenances showed that the seed quality of P.decomposita had obvious correlation among different provenances.Seed length was significantly correlated with seed width,length-width ratio of seed and seed viability;seed width was significantly correlated with seed moisture content,length-width ratio of seed,1000-grain weight and seed viability;seed purity was significantly correlated with seed moisture content and 1000-grain weight;1000-grain weight was significantly correlated with seed moisture content and seed viability;seed viability was significantly correlated with seed moisture content,and seed morphology further affects seed quality.?3?The correlation analysis between seed quality and environmental factors of P.decomposita from different provenances showed that latitude,altitude,annual average rainfall and annual average temperature were the main environmental factors affecting the seed quality of P.decomposita.Latitude had a significant positive correlation with seed width,1000-grain weight and seed moisture content,a significant negative correlation with seed purity,an extremely significant positive correlation with annual average temperature,seed purity and seed viability,and a significant negative correlation with seed width,1000-grain weight and seed moisture content.There was a significant positive correlation between altitude and seed purity,and a very significant negative correlation between elevation and seed vigor.?4?Through grade evaluation on seed quality of P.decomposita with different provenances,the cluster analysis results showed that the six tested provenances could be divided into three categories:the first category included Danba County,Li County and Kangding provenances,the values of seed length,seed width and 1000-grain weight in this group were large,and the annual average temperature was low?<6.8??;the second category included Malcon and Xiaojin County provenances,which had the characteristics of moderate seed length,seed width and 1000-grain weight;the third category included Jinchuan County provenance,which had the characteristics of small seed length,seed width and 1000-grain weight and low seed moisture content.The results of principal component analysis showed that the cumulative contribution rate of the first three principal components reached 93.405%.Seed width,seed moisture content,seed viability,seed coat thickness and 1000-grain weight could be used as the main indexes for seed quality rating,and seed vigor,seed length-width ratio,seed clarity and seed length could be used as reference indexes.Preliminary screening showed that the seed quality of Li County,Danba County and Kangding provenances reached excellent,the seed quality of Malcon and Xiaojin County provenances reached qualified,the seed quality of Jinchuan County provenance was unqualified,which was not suitable for P.decomposita excellent provenance.?5?The study on the effect of different matrix and GA3 on the rooting of P.decomposita showed that the seeds treated with 100-200 mg/LGA3 could significantly improve the rooting percentage??0.98?and the rooting rate(?0.08 d-1)of P.decomposita,and the difference among the three concentrations?100,150,200 mg/L?was not significant.When the seeds were treated with 200 mg/LGA3 and planted in fine sand soil,the rooting?1.00?and lateral root growth percentage?0.13?were the highest,the days of scarification for first seed was 12.25 days,the days of first seed rooting was 26.43 days and rooting duration were the shortest?21 days?,and the rooting rate was the fastest(0.10 d-1),which was the most suitable rooting combination.?6?The study on the influence of different matrix and GA3 on the germination and growth of P.decomposita showed that the seeds planted in the matrix with fine sand:yellow soil=1:1,the initial germination period,germination percentage and germination rate were significantly better than those in the other two matrices under the same conditions;the effect of GA3 on breaking the dormancy of the hypocotyls of P.decomposita seeds was closely related to the length of the taproot.When L>30 mm,GA3 treatment could release the dormancy of P.decomposita hypocotyls in advance,improve the germination percentage and germination rate.There was no significant difference among the three concentrations of GA3?50,100,150 mg/L?.The seeds with L>30 mm were planted in the matrix with fine sand:yellow soil=1:1,treated with 50mg/LGA3,the germination percentage of P.decomposita was the highest?0.89?,and the initial germination period was 45.63 days.The germination rate was 0.97 d-1,which was the most suitable seed germination combination.In the primary stage of seedling growth,the matrix had a significant effect on the height and leaf number of P.decomposita seedling,and the seedlings planted in the matrix with fine sand:yellow soil=1:1 had the best growth potential;compared with the control group,GA3 could effectively promote the growth of P.decomposita leaf,when L>30 mm,the average seedling height and leaf number of P.decomposita increased with the increase of GA3concentration;the seeds with L>30 mm were planted in the matrix with fine sand:yellow soil=1:1,and treated with 100 mg/LGA3,the growth indexes of each seedling reached the maximum,the seedling height was the highest?12.44 cm?,and the number of leaves was the largest?3.50 pieces?. |
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