Two new sesquiterpenes from the aerial parts of Schizonepeta tenuifolia.

Two new sesquiterpenes named petafolias A-B were isolated from the aerial parts of Schizonepeta tenuifolia. Their structures were elucidated by various spectroscopic techniques (UV, IR, MS, CD, 1D, and 2D NMR).

[Isolation and identification of pathogen of seedling blight of Platycodon grandiflorum].

OBJECTIVE: To isolate and identify pathogen of the seedling blight occurred in Platycodon grandiflorum. METHOD: The morphological observation, rDNA ITS sequence analysis, and Koch's postulates were used to identify the isolates of the causal agent. RESULT: The isolates of the causal agent was Rhizoctonia solani. CONCLUSION: The result confirmed that R. solani is the pathogen of seedling blight of P. grandiflorum.

[The performance of agronomic traits in F1 crossing combinations derived from male sterile line of Platycodon grandiflorum].

OBJECTIVE: To determine the possibility of heterosis utilization by male sterility in Platycodon grandiflorum. METHODS: The analysis of variance, heterosis over standard and correlation on 12 agronomic in 18 crossing combinations were carried out. RESULTS: Except the dry weight of upground part of plant, the length of main root and the diameter of middle part of the main root, all other agricultural traits were different significantly among the 18 F1 combinations. The diameter of middle part of the main root had the highest coefficient of variation and the ratio of fresh weight of main root and total root had the lowest coefficient of variation,which was 85.42% and 3.66%, respectively. For the traits related to the yield of root,average heterosis over standard in fresh main root and total root was 42.35% and 45.50%, respectively; For the traits related to the form of root, the diameter of up part and middle part of main root had a middle heterosis over standard, which was 12.38% and 29.97%, respectively. The shoot growth was significantly related to its root growth in combination (0.651). The number of nodes on main stem was significantly related to five out of six traits of root in hybrids. CONCLUSION: Variation of agricultural traits in crossing combination is rich, heterosis of traits in root is evident,and F1 hybrids with good yield and the forms could be selected from these combinations. The Platycodon grandiflorum of crossing combinations have reasonable morphological characteristics, and the number of nodes of main stem could be taken as the selected index. All show us that the heterosis by the male-sterility could be utilized in the breeding of Platycodon grandiflorum.

[Breeding of new varieties "zhongchai no. 2" and "zhongchai no. 3" of Bupleurum chinense].

OBJECTIVE: To breed new varieties with better uniformity and commercial quality as well as higher saikosaponin contents. METHOD: The excellent germplasm resources were selected from "zhongchai no. 1" population. Single plant method was applied to get better varieties. All the breeding material was investigated according to morphological characters, agronomic characters and the contents of saikosaponin a and saikosaponin d. The experiments of comparative test and varieties regional test were carried out. RESULT: The bred new varieties of "zhongchai No. 2" and "zhongchai No. 3" had better uniformity. The dark brown roots ratios of the two varieties were 83.2%, 89.9%, respectively. The contents of saikosaponins (a + d) of the two varieties reached 1.31%, 1.02%, respectively. CONCLUSION: "zhongchai No. 2" and " zhongchai No. 3" both had the advantages of better uniformity, darker brown roots and higher saikosaponin contents.

[Characteristics and abortion cytological pathways of male sterility of Bupleurum chinense].

OBJECTIVE: To study the characteristics of male sterility of Bupleurum chinense and further explore the developmental period and reason of abortion for the male sterile plants. METHOD: The morphological characteristics of B. chinense male sterile and normal plants were investigated and compared. The anther development process and pollen viability of two types of plants were examined by microscopic assay. RESULT AND CONCLUSION: The shapes and sizes of anther and filament were different between the male sterile and the normal plants. For the male sterile plant's, the filament size was no more than 1/2 of that of normal plants and the anthers were shriveled, failed to dehisce and pollinate naturally, and the pollen grains in the anthers had no vitality. Other morphological characteristics were similar between two types of plants. The main reason leading to male sterility of B. chinense was the abnormal development of tapetum cells with two circumstances. The one is that the tapetum cells degraded early during the period of microsporocyte phase to tetrad phase and the other is that the tapetum cells proliferated with delayed degradation in the tetrad to uninucleate phase.

[Heterosis analysis of the main agronomic characters of Platycodon grandiflorum].

OBJECTIVE: Breeding the good varieties characters of Platycodon grandiflorum. METHODS: 20 combination, derived from 2 x 10 incomplete diallel cross with 2 male sterile lines and 10 four-generation inbred lines, analysis the 13 agronomic characters. RESULTS: The agronomic characters of F1 has obvious heterosis. Dry plant weight and fresh root weight have the largest heterosis. Their middle parent heterosis (MPH), high parent heterosis (HPH) and heterosis over CK (CH) were 96.07%, 62.62%, 116.21%, 108.99%, and 111.98%, 113.47%, respectively. CONCLUSION: The F1 hybrids derived from the crossing of male sterile lines and in-bred lines have obvious heterosis. It applied the hybrid heterosis breeding is an effective way for the new variety of Platycodon grandiflorum.

[Comparison on agronomy and quality characters of selective strain of Schizonepeta tenuifolia].

OBJECTIVE: With the purpose of selecting adequate quality and high production of Schizonepeta tenuifolia, the comparative experiments were carried out on different strain of S. tenuifolia in 2007. METHOD: The test fields were divided into blocks randomly, and the agronomy characters were investigated in harvest time; the content of volatile oil was measured by steam distillation and the pulegone were determined by HPLC. RESULT: The yield of S4 was 18.63% and 29.99% higher than that of CK1 and CK2, respectively. The contents of volatile oil and pulegone were also higher than those of CK and other strains in this test. CONCLUSION: S4 shows the advantages of high production, strong disease resistance and high active components. S4 would be extended as the good breed in production.

[Study on the stigma/pollen vigor and self-compatibility of Platycodon grandiflorum].

OBJECTIVE: To provide the basal data for the breeding and cultivation of Platycodon grandiflorum. METHOD: The field investigation and pollination by bagging were carried out. TTC(2,3,5-triphenyl tetrazolium chloride) solution was used to test the pollen vigor. RESULT: The stigma life-span of P. grandiflorum was about 9 days, however the optimal time for pollination is 4-6 days after the petals opening, with the stigma was splitting lightly or significantly. When the petals opened, the anther began scattering pollen, and finished in the same day. The pollen vigor was about 81.4% at the beginning, and decreases to 27.6% three days later. The pollen vigor still remains 64.4% three days later, when the flower was kept in the desiccant. The natural fructification rate of self-flower-pollination was 4.8%. The fructification rate and compatible index was about 62.7% and 54.6, respectively, when the self-plant-pollination performed by hand. They decreased to 12.8% and 6.5 when the pollination was implemented during the flowering period. CONCLUSION: Low fructification percentage of self-flower-pollination attributes to the difference of maturing period of pistil and stamen, as well as the short pollen life-span of P. grandiflorum. The compatibility of self-plant-pollination is high during flowering period when pollination performed by hand. The life-span of the pollen can be prolonged significantly when keeping in the dry environment.

[Plant growth analysis of Bupleurum chinense].

OBJECTIVE: To learn the development characteristics of Bupleurum chinense DC. for the cultivation fundament. METHOD: Mature and intact plant samples of different growing periods are studied by the method of plant growth analysis. RESULTS: The plant organs are composed of root, root crown, stalk, basal leaves, stem leaves, branches and leaves, apical and lateral inflorescences. Dry substance in the branches of the first and second level was 93.8% of that in all branches. Though the branches of third or fourth level were relatively weak, their amount was large. The root-shoot ratio with the value 0.19 was especially low. Lateral inflorescences of third or fourth level were found commonly in the population, but the first and second ones were the majors part. About 38.1% dry substance was used for the development of propagation organ. The length of main root was only 17.2 cm, its weight was nearly same as that in the lateral roots. CONCLUSION: Short cultivated history of B. chinense are still maintained some significant wild characteristics, so they don't accord with the demand of the objective gathering in the root. It may be resolved with artifical regulation and breeding.

[Study on organogenesis and dry substance accumulation of Bupleurum Chinense].

OBJECTIVE: To learn the development characteristics of Bupleurum chinese DC. and to provide the cultivation fundament. METHOD: Plant samples of different growing periods were collected and investigated. RESULTS: It was found that the development stages of B. chinense could be divided definitely into emergence of seedings, seedling, elongation of internode, flowering and fruiting, and dormancy. During its life, cotyledon, basal leaves and stem leaves appeared and died away in turn, and the stem extended to its full length in one month. The root reached its top length during seedling stage, and its diameter increased quickly from July to August. The dry substance accumulated in aerial part of the plant increased quickly, and that in root increased by 42.4%, 94.0%, or 40.1% respectively, from mid July to mid August after stem elongation beginning, from mid September to mid October, or from mid October to the date of harvesting. CONCLUSION: Management methods and planting technologies of B. chinense should be mapped out according to the different characteristics of its three key growing stages.

[The influence of seed maturity and seed coat on the germination of Bupleurum chinense and B. falcatum].

OBJECTIVE: To investigate the factors influencing the seed germination of Bupleurum chinense and B. falcatum. METHOD: The seeds of different maturity, and the seeds whose coat were removed or nicked before dipping in water, were germinated in a light growth chamber. RESULT: The different inflorescence level represents different development period. Seeds harvested from cultivation have different maturity. The germination rate of the seeds in period I to III was nearly zero, and it was significant different from period IV to VII. The seed coat is not an obstacle for water absorption or gas exchange, but its removal led to significant increase of seed germination rate. However, to dip the seeds without coat into water for 48 h had no more effect on germination. CONCLUSION: The seed maturity and germination inhibitors in seed coat are two important factor influencing seed germination in B. chinense and B. falcatum.