Post-last glacial maximum expansion of Y-chromosome haplogroup C2a-L1373 in northern Asia and its implications for the origin of Native Americans.

OBJECTIVES: Subbranches of Y-chromosome haplogroup C2a-L1373 are founding paternal lineages in northern Asia and Native American populations. Our objective was to investigate C2a-L1373 differentiation in northern Asia and its implications for Native American origins. MATERIALS AND METHODS: Sequences of rare subbranches (n = 43) and ancient individuals (n = 37) of C2a-L1373 (including P39 and MPB373), were used to construct phylogenetic trees with age estimation by BEAST software. RESULTS: C2a-L1373 expanded rapidly approximately 17.7,000-14.3,000 years ago (kya) after the last glacial maximum (LGM), generating numerous sublineages which became founding paternal lineages of modern northern Asian and Native American populations (C2a-P39 and C2a-MPB373). The divergence pattern supports possible initiation of differentiation in low latitude regions of northern Asia and northward diffusion after the LGM. There is a substantial gap between the divergence times of C2a-MPB373 (approximately 22.4 or 17.7 kya) and C2a-P39 (approximately 14.3 kya), indicating two possible migration waves. DISCUSSION: We discussed the decreasing time interval of "Beringian standstill" (2.5 ky or smaller) and its reduced significance. We also discussed the multiple possibilities for the peopling of the Americas: the "Long-term Beringian standstill model," the "Short-term Beringian standstill model," and the "Multiple waves of migration model." Our results support the argument from ancient DNA analyses that the direct ancestor group of Native Americans is an admixture of "Ancient Northern Siberians" and Paleolithic communities from the Amur region, which appeared during the post-LGM era, rather than ancient populations in greater Beringia, or an adjacent region, before the LGM.

[Investigation of production status in major wolfberry producing areas of China and some suggestions].

To investigate the production status and the safety influence factors of wolfberry in China. We investigated the detailed factors which affect the quality safe of wolfberry in the periods of July-August 2013 and July-September 2009. The factors include fertilizing patterns, the used pesticide and preliminary process wolfberry. The factors were discussed according to the results of investigation, and suggestions were proposed for the management and production departments of wolfberry.

[Screening for virulence strains of Metarhizium against Dorysthenes hydropicus pascoes].

OBJECTIVE: The aim of the present study was to screen the Metarhizium strains with high virulence against the larvae of Dorysthenes hydropicus, a serious pest of Citrus grandis. METHOD: Thirty six strains of Metarhiziums were isolated from the soil of C. grandis GAP base and collected from other institutions, and the pathogenicity of these strains against 1st instar larvae of D. hydropicus was detected at concentration of 1 x 10(8) conidia/g. The high violence strains against D. hydropicus were cultivated in sabouraud dextrose yeast medium at first, then transfer to rice grain. And the sporulations of these violent strains against D. hydropicus were detected. RESULT: Twenty-eight strains showed virulence against D. hydropicus by preliminary study, and 7 strains of them were collected for further study, 6 of the 7 showed high virulence, the highest cadaver rate was higher than 74%. The conidia production of strain 1 and strain 4 were 2.35 +/- 0. 25 (1 x 10(9) conidia/g), 2.21 +/- 0.27 (1 x 10(9) conidia/g), respectively, showed significantly higher than other strains. CONCLUSION: Strain 1 and strain 4 of the 36 Metarhiziums strains showed high virulence against D. hydropicus, and the highest sporulation ability, so they have a best application prospect.

[Primary studies on biological characteristics of Dorysthenes hydropicus].

OBJECTIVE: To study the biological characteristics of Dorysthenes hydropicus in the farm of Cirtus grandis, and offer scientific evidence for prevention and controlling of D. hydropicus. METHOD: Indoor-rearing and light trap were applied to study the biological characteristics, development course and harmful effect of D. hydropicus. RESULT: D. hydropicus reproduces one generation in 1-2 year in Guangdong province, and overwinters in the form of larvae. Its imago comes out of the earth mainly in late May after mature. The body length has great individual diversity normally ranged from 25-60 cm, It also shows strong phototaxy. One lamp can trap more than 2 000 of them per night. Female imago has a large egg load with the maximum amount of 543. The eggs hatching is in depth of 1-3 cm soil. The dominant hatching period of egg is from late June to early July, and hatchability is over 85%. The living space of larva ranges from 15-60 cm in soil. D. hydropicus has caused serious harm and lead to thousands of Cirtus grandis trees death every year. CONCLUSION: Dorysthenes hydropicus showed serious threat to the growth of Cirtus grandis and should be prevented and controlled.

[Study on reproduction biology of Cistanche deserticola--seedling emergence and flowering].

OBJECTIVE: To study the reproduction characteristic of Cistanche deserticola. METHOD: The reproduction characteristic and growing dynamic in Ningxia plantation were investigated, the contents of boschnaloside and echinacoside were determined during reproduction period. RESULT: The germination period of C. deserticola was in the first ten days of the month, the duration from the germination to flowering lasted about one month. The contents of boschnaloside and echinacoside decreased during reproduction period. CONCLUSION: The reproduction period of C. deserticolais lasts about two months, germination period of C. deserticola is the suitable harvest time.

[Occurrence and control of Loxostege stieticatis on host plant Haloxylon ammodendron to Cistanche deserticola].

The investigation of the occurrence and pesticide experiments of Loxostege stieticatis on Haloxylon ammodendron showed that Loxostege stieticatis is an explosive pest; it can be controlled with lower toxic pesticides such as deltametrin; the innocuous comprehension measure should be a good choice to control in field.

[Study on residue analysis method of imidacloprid in Ephedrae sinica].

OBJECTIVE: To establish residue analysis method of imidacloprid in Ephedra sinica by HPLC. METHOD: Imidacloprid was extracted with dichloromethane, cleaned up with chromatography column, then separated on Spherisorb C18 column by using Methanol-water (20:80), detected at 270 nm. RESULT AND CONCLUSION: The limit of detection (LOD) and limit quantification (LOQ) were 0.4 x 10(-9) g and 0.02 mg x kg(-1), mean recovery and related standard deviation (RSD) were 85.37%-90.65% and 2.23%-3.45%. It is concluded that the method could satisfy the pesticide residue analysis demands in sensitivity, accuracy and precision.

[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.

[Study on yield and quality of Scutellaria baicalensis from different habitats].

OBJECTIVE: To compare the economical characters, yield characters and major effective ingredient content of Scutellaria baicalensis from different habitats. METHOD: The characters were studied by field randomized block test combining analysis of variance, correlation analysis and quality analysis. RESULT: There are significant differences in yield and quality of the crude drugs from different habitats. CONCLUSION: The crude drug from Pingyi (Shandong province) is better than those from other habitats.

[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.

[Presearch on preventing the medicinal plant diseases with Trichoderma harzianum preparation].

OBJECTIVE: To control the medicinal plant diseases with the preparation of Trichoderma harzianum. METHOD: Antagonistic action of the preparation to the pathogens of the medicinal plants in vitro, and controling effects of the preparation on these diseases in greenhouse and in the field were tested. RESULT: The test in vitro showed that Trichoderma harzianum, used as a biocontrol factor, had stronger antagonistic action to Fusarium equiseti, Sclerotinia sp. and Rhizoctonia solani which were the medicinal plant pathogens of Astragalus membranaceus, Glehnia littoralis and Panax quinquefolium respectively. Biological controling effects on sclerotium root rot of Glehnia littoralis were 83.6% and 72.5% respectively in greenhouse and in the field with the preparation of Trichoderma harzianum. And controling effects on root rot of Astragalus membranaceus and seedling damping-off of Panax quinquefolium were 80% and 60% respectively in the field. The dosage of the preparation used in the field was 10 g.m-2. CONCLUSION: The preparation of Trichoderma harzianum can be used as a substitute for such chemicals as Carbendazim. Using the preparation to control medicinal plant diseases provides a technical safeguard for the good agricultural practice of medicinal plants.

[Study on gallnuts development and its tannin amount].

OBJECTIVE: To find out the suitable time for collecting gallnuts. When Kaburgaia rhusicola parasailed on leaflets of Rhus potainii, the parts of the leaflets developed into gallnuts. METHOD: The regulation of development and tannin amount during whole growing stage were studied. RESULT: K. rhusicola lived in gallnuts for about 80 days. The gallnuts developed quickly during earlier stage and slowly during later stage. Gallnuts maturated from 12th, July to 30th, July, which had no relations with the size and the time for forming, but had relations with development at earlier stage. It developed quickly with earlier maturation and developed slowly with later maturation. Its tannin amount kept stable during the whole growing stage. CONCLUSION: The best harvesting days are those shortly after 7th, July.

[Study on the pollination characteristic of Cistanche deserticola].

OBJECTIVE: To study the Pollination Characteristic of C. deserticola. METHOD: Four pollination methods were used, cross pollination coming different plant, cross pollination in one plant, wind pollination and no-pollination. RESULT: Cross pollinations coming different plant are fructiferous. The average fructication rate of cross pollination coming different plant is 94.1%; the average fructication rate of cross pollination in one plant is 52.2%; The seed qulitity of cross pollination coming different plant is better than the cross pollination in one plant. CONCLUSION: Cross pollinations coming different plant have a high quantity and quality of seeds of C. deserticola.

[Applied studies of biological control techniques on healthful Chinese crude drugs].

Medicinal plants always suffer from diseases and pests in their cultivation and growing, and the yield and quality are reduced. At present, chemical pesticide is mainly used to control the diseases and pests. The long-term use and over-use of pesticide result in pesticide residue, pests resistance to pesticide, water and soil pollution and other environmental contamination. It is necrssary to provide the integrated pests management, including new technology of biological control for developing green drug. This project makes research on the following aspects: 1. Applied studies on bethyloid wasp (Scleroderma guani) control for stem borer; 2. To develop Trichoderma spp. and use it to control the diseases of medicinal plants; 3. Applying Agro-antibiotics 120 to control phytophthora root rot of ginseng; 4. Researches on application of entomopathogenic nematodes against ten-spotted lema (Lema decempuntata) et al.

[Biological effect of seed-coating in Carthamus tinctorins].

OBJECTIVE: To study the Biological effect of seed-coating in Carthamus tinctorins. METHOD: Two kinds of seedcoating chemicals SCF1 and SCF2 were used in this experiment, the seed YM-99 and 27981-99 were coated by three kinds of ratio of seedcoating chemicals to seed. It was investigated that the germination energy and germination percentage in the room and the emergence rate, seedling stage growing, pest in the field. RESULT: Seedoating can improve the emergence rate and seedling stage growing, it also can effectively control aphid, rust and virosis during the growing period in C. tinctorins. CONCLUSION: Seedcoating has significant biological effect in C. tinctorins.

[Investigation on occurrence of lycium pests and their natural enemies].

OBJECTIVE: To Provide the scientific basis for controlling the lycium pests. METHOD: The kinds and number of pests and their natural enemies were investigated at regular intervals and on the fixed trees. RESULT: There are 13 kinds of lycium pests and 17 kinds of natural enemies, the occurrence of which are closely related. CONCLUSION: Natural enemies can control aphids and psyllidae effectively, but ten-spotted lema and Epithrix sp. must be controlled by pesticides.