Genetic And Environmental Impact On The Yield And Quality Of The Radix Scutellariae And Its Mechanism

Radix Scutellariae is the dried root of the perennial herb Scutellaria baicalensis Georgi in Scutellaria L. of the family Labiatae, which is one of widely used traditional Chinese herbal medicine. Because of the decreasing of wild Radix Scutellariae resources, cultivated Radix Scutellariae has become the main source of Radix Scutellariae. However, presently, high yield and high quality of cultivated Radix Scutellariae has not been formed. Because of the wild and provenance mixed of cultivated seeds the medicinal materials quality is intermingled. This paper explored the effects and mechanism of genetic and environmental factors on yield and quality of medicinal materials of S. baicalensis by investigating 57 offsprings of S. baicalensis which collected from its major regions. And combining the field experiment and laboratory analysis, the plant growth characteristics, physiological characteristics, medicinal materials yield, medicinal materials appearance characters and chemical composition content were tested. Multi-provenances of three origins tests were carried out, therefore guidance for selective breeding of excellent Radix Scutellariae would be provided. The main results of the research were as follows:1. The multipoint provenance test showed that:The medicinal materials yield of S. baicalensis was mainly affected by environment. The percentage of environment variance (19.58%) in total sum of square of medicinal materials yield of S. baicalensis was more than the percentage of gene (14.67%) and the percentage of genetic and environmental interactions (16.29%). This data showed that the environmental effect was greater than genetic effect on medicinal materials yield of S. baicalensis, and the effect of genetic and environmental interactions was slighter. Thus it should give a priority to the cultivation place in breeding the yield of S. baicalensis,. The medicinal materials yield of S. baicalensis had a positive correlation with latitude, longitude, altitude, the annual precipitation and the annual average humidity. In choosing the cultivation place, it should be considered that the area with northeast, high altitude, rainfall and high annual average humidity as the exellect productive area.2. The single point provenance test showed that:Significant differences existed in different provenances medicinal materials yield of S. baicalensis of same area during annual yield (P< 0.01), the broad-sence heritability of the single point test was 0.5902, which shows medicinal materials yield of S. baicalensis in annual stage were half gene-controlled. The analyzing of different provenances of S. baicalensis of biennial and annual showed that tendency of 47% annual materials kept constant,26% relatively became less, and 27% become more, which showed that the rate of the production influenced by the plant itself was 47%. Conclusion was that genetic also effect the production of medicinal materials. Therefore, selecting seeds was also important in practice in high yield and high quality cultivation of radix scutellariae.3. The relevant analysis of medicinal materials yield of S. baicalensis and overground growth characteristics showed that: The medicinal materials yield of S. baicalensis had significant or very significant positive correlation with 10 indicators which included plant form, plant color, plant height, plant range, secondary branch plant, leaf form, leaf color, leaf length and leafstalk length, positive but insignificant correlation with the first-flowering date, coefficient from 0.141 to 0.283. The data showed that medicinal materials yield of S. baicalensis had a gradually increasing tendency with plant height and range. The later the first-flowering date was, the higher the yield would be. In another word, S. baicalensis with a high plant height and late first-flowering date would have a higher output, in the contract the plant with small early flowers type would have a lower output.4. The multipoint provenance test showed that:The appearance characteristics of S. baicalensis were mainly affected by environment and genetic-environmental interactions. Because that the genetic-environmental interactions variance of root length and total lateral root number which were 31.72% and 27.00% in total square are larger than the percentage of environment (12.63% and 18.73%) and genetic (10.50% and 8.26%) in total square, the percentage of gene variance (20.83%) for diameter head in total sum of square was larger than percentage of environment (17.00%) and genetic-environmental interactions (17.20%), the environment variance percentage(25.80%) of head from reed 10 centimeters in diameter was larger than percentage of genetic (13.35%) and genetic-environmental interactions 21.44%.5. The single point provenance test showed that:Significant differences existed in different provenances of S. baicalensis of the root length, reed from head diameter and total lateral root number of same area during annual yield (P<0.01). The broad-sence heritability of which were 0.7315,0.5719 and 0.6267. It had no significant differences in head from reed 10 centimeters in diameter (P>0.05). It showed that the root length, reed from head diameter and total lateral root number was halfly controlled by gene, head from reed 10 centimeters in diameter was slighter controlled by gene.6. The multipoint provenance test showed that:Baicalin and wogonoside contents were mainly controled by genetic. Baicalein and oroxylin A contents were controlled by gene and environment, at the same time the genetic function could not be ignored. The environment effect on wogonin was large, while less was gene effect. Because the gene variance percentages of baicalin and wogonoside were 55.43% and 57.92%, more than the percentage of environment which were 1.37% and 0.85% and interactions of genetic and environmental which were 43.21% and 41.23%. The percentage of interactions variance of baicalein and oroxylin A of the sum of total squaire which were 46.65% and 69.20% was more than the percentage of gene (39.53% and 28.24%) and environment (13.82% and 2.52%).7. The single point provenance test showed that:The contents of baicalin, wogonoside, baicalein, wogonin and oroxylin A of different provenances of S. baicalensis of annual and biennial roots had a significant difference (P<0.01). The broad-sence heritability of those 5 chemical compositions was estimated, which were 0.6354,0.5645,0.6197,0.5856 and 0.5976 of annual stage,0.5702 and 0.7132 of biennial stage. It showed that the content of baicalin and wogonoside of annual and biennial was halfly controlled by gene, which showed a good potential genetic improvement. The contents of baicalein, wogonin and oroxylin A of annual S. baicalensis also were hardly controlled by gene.8. Analysising of the content of per plant chemical composition of different provenance of biennial and annual S. baicalensis showed that 44% baicalin,54% wogonoside,30% baicalein,38% wogonin and 52% oroxylin A kept constant.Peculiarity and creativity:The effects of genetic factors, environmental factors and the interaction of two factors on the medicinal material yield and quality, and the mechanism of genetic factors, environmental factors and the interaction of two factors were discussed, which could be helpful for further breeding study.