ISSR Analysis on Genetic Diversity of the 34 Populations of Oryza meyeriana Distributing in Yunnan Province,China

The genetic diversity of the 34 populations of wild rice Oryza meyeriana Baill. distributed in Yunnan Province, China was analyzed using 13 inter-simple sequence repeat （ISSR） markers. A total of 168 bands were amplified, of which 135 polymorphic bands were discovered and the percentage of polymorphic bands （PPB） was 80.36%. A genetic diversity was revealed as Nei＇s gene diversity （H） = 0.2666 and Shannon information index （I） = 0.4028 at population level. The 34 populations were divided into different groups based on administrative regions, latitude and longitudes, river areas, altitudes of their origins, and their indexes such as Na （number of alleles）, Ne （effective number of alleles）, H, I and PPB were calculated. Richer genetic diversity was found in the wild rice populations distributed in Simao Prefecture than that in Lingcang Prefecture or Xishuangbanna Prefecture whereas the least genetic diversity was in Baoshan Prefecture or Dehong Prefecture. Rich genetic diversity was also discovered in the wild rice populations originated from higher than 710 m altitude around the middle and lower reaches of the Lancang River belonging to the Pacific Ocean drainage system. The 34 populations could be classified into two groups, one group covered the wild rice distributing in Simao Prefecture only while the other group covered ones in Lingcang, Xishuangbanna and Dehong Prefectures. The issue on how to effectively conserve the wild rice germplasm was discussed.     

Prokaryotic Expression,Purification and Characterization of a Novel Rice Seed L.ipoxygenase Gene OsLOX1

Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize the OsLOX1 gene from rice seeds, the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a（＋） and transformed into Escherichia coil BL21 （DE3）. Expression of the fusion protein was successfully induced by isopropyl-β-D- thiogalactopyranoside （IPTG） and the purified recombinant protein was obtained by His.Bind Kits. Further assay showed that the purified recombinant protein exhibited the LOX activity. The optimum pH was 4.8 （acetate buffer） and the optimum temperature was 30℃ for the above enzyme. Thus, the recombinant might confer an available usage for the synthesis of jasmonate in vitro, and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.     

Optimization of a Reaction System of Sequence Related Amplified Polymorphism and Segregation of Polymorphic Loci in an F2 Population of Rice

An effective PCR protocol for detecting the sequence related amplified polymorphism （SRAP） in rice was developed. One hundred and ten pairs of SRAP primers were used for segregation analysis in an F2 population derived from a cross between Shennong 606 and Lijiangxintuanheigu. Among the 110 primer pairs, 35 pairs generated 143 polymorphic bands with an average of 4.09 polymorphic bands per primer pair, and 24 pairs （16.78%） showed the genetic distortion （P〈0.05）. Of the 24 primer pairs, 12 pairs deviated toward the male parent Shennong 606 and 11 pairs toward the female parent Lijiangxintuanheigu, only one toward heterozygote. It was found that the segregation distortion might be caused by the joint gametic and zygotic effects.     

Discovery of and Preliminary studies on a Rapid-Leafing Rice Genotype at the Vegetative Growth Stage

The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.     

Elongation of the Uppermost Internode for Changxuan 3S,a Thermo- Sensitive Genic Male Sterile Rice Line

Changxuan 3S, a thermo-sensitive genic male sterile （TGMS） rice line with eui gene, is derived from the TGMS rice line Pei＇ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei＇ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day （flowering）, being 2.1-fold as that of Pei＇ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei＇ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures.     

A Study on Physiological Character of Fresh Tea Leaves in Different Cold-Resistant Varieties简

In order to reveal the cold resistant mechanism of tea plant,two varieties with different cold resistances were studied.The activities of catalase （CAT）,peroxidase （POD）,superoxide dismutase （SOD） and polyphenol oxidase （PPO） were investigated,and the contents of soluble protein,sugar and malondialdehyde （MDA） were determined in fresh tea leaves in the autumn.The results showed that the activities of POD and the content of soluble sugar were both much higher in the variety with strong cold resistance,and the content of soluble protein was associated with the cold resistance,while the cold resistance of the plant was not related with the activities of the CAT,SOD and PPO,and the content of MDA.It is considered that the activity of POD and contents of soluble sugar could be used as indicators to identify the cold resistance of tea varieties.     

Studies on Umami Taste of Tea

Umami is one of the five basic tastes and an important taste attribute of green tea.Amino acids are major components contributing to umami taste and the top three amino acids in tea are theanine,glutarnic acid and aspartic acid.Trace of umami taste components adenosine monophosphate （AMP） and guanosine monophosphate （GMP） were detected in tea.Levels of umami taste components varied with tea cultivar,environmental conditions,fertilizer and processing method.The taste threshold of amino acids differentiated greatly and its DOT （dose over threshold） is an important indicator evaluating its contribution to umami taste.     

Applications of Green Tea Extract in Bakery Products

Green tea extract （GTE） is a rich source of tea catechins with antioxidative,anticarcinogenic and antiarteriosclerotic activities and it has been applied in food such as bakery products to provide health benefits and extend the shelf life.This review outlines the stability of green tea catechins during baking process of bakery products supplemented with GTE and the effects of GTE on the functional properties,sensory properties,physical characteristics and Maillard reaction of bakery products.     

Tea Seed and Its Bioactive Functions

Tea seed is a byproduct in tea production and also a source of nutritional and bioactive compounds.There have been studies showing that extracts of tea seeds offered many physiological functions including anti-inflammatory,anti-oxidant,anti-tumor,anti-obesity,hepatoprotective and gastroprotective effects.The tea seed oil is also an acceptable biodiesel and the saponin-rich tea seed meal can be used as vermicide to expel earthworms from the soil of golf courses and sports fields.The bioactive functions of tea seed extracts and their potential uses in agricultural and industrial sectors were reviewed in the present paper.     

Development of New InDel Marker to Detect Genotypes of Rf-la Conferring Fertility Restoration of BT-Type Cytoplasmic Male Sterility in Rice

Restorer line breeding is an important approach to enhance the heterosis and improve the yields of japonica hybrid rice. To improve the selection efficiency of restorer lines for BT-type cytoplasmic male sterility （CMS） in japonica rice, a functional marker InDeI-Rf-la based on the difference of nucleotide sequence in Rf-la locus between BT-type CMS lines and restorer lines was developed to detect the genotypes of different rice materials. Conventional indica rice varieties, restorer and maintainer lines without 574 bp deletion could restore the fertility for BT-type CMS in japonica rice. By contrast, most conventional japonica rice varieties except Aichi 106 and Yijing 12, with genotype of rf-larf-la showed the 574 bp deletion maintained sterility for BT-type CMS lines. To further verify the effect of genotyping detection in Rf-la locus, this marker was also used to amplify the genomic DNA in different japonica rice restorer lines, CMS lines, hybrids and F2 segregation population, and three genotypes in Rf-la locus could be distinguished distinctly. Therefore, the marker InDeI-Rf-la could be widely used for genetic id~ntifio.~tinn ~nd m~rkp.r-~.~.~i~fp.d .~.tAr.tinn （MA.~ in hr~=dinn i~nnnir~ r~fnr~=r lin==~     

Fluoride in Tea and Its Risk Assessment

Tea plant absorbs from soil a large amount of fluorine （F） which is accumulated in leaf,resulting in elevated F concentration in tea.It is a controversial topic whether the fluoride in tea is associated with fluorosis.The research advances in F variation of various kinds of tea,factors influencing F level in tea and the associated health risk assessment were reviewed in the present paper.The F level in tea increases with the maturity of the tea leaf.Brick tea had a high F content because it was prepared using mature shoots and old tea leaves as raw material.Some low grade UK supermarket economy teas contained elevated F comparable to the Chinese brick tea.Tea F level is also affected by tea cultivar,soil condition,tea processing method and tea infusion preparation method.     

Study on the Retention Rate of Green Tea Catechins Components and Tea Polyphenol by Different Processing Technology

The aim of this research was to explore the effect of fixation,rolling,and drying processing technology on the retention rate of green tea catechins components and tea polyphenol.Different fixation processes （rotary drum-firing,microwave,steam-blasting）,rolling process （weight of rolling,gently press rolling and traditional rolling）,drying process （stove drying,roasting dehydration,baked fried drying） were adopted.The effect of different tea processing technology on the retention rate of catechins component and tea polyphenol was analyzed.It showed that the microwave fixation process,gently press rolling process,baked fried dry process were beneficial to keep high levels of EGCG,C,EGC,EC,ECG.     

Effect of Different Drying Methods on the Volatile Compounds Jinmudan Oolong Tea

Jinmudan,a new tea variety from Fujian Province has an excellent quality with a unique aroma like magnolia frogrance.To monitor the changes in the tea volatile compounds during the Jinmudan Oolong tea manufacturing （drying） process,the volatiles of tea samples were extracted and analyzed.Characteristic volatile compounds in Jinmudan Oolong tea were nerolidol,α-famesene,linolenic acid,palmitic acid,indole,phenylacetaldehyde,cisjasmone,β-phenylethanol,etc.The content of nerolidol was the highest in four tested samples.The composition of the volatile compounds in microwave drying sample was simple,but its concentration was high,in which the main volatile compounds were alcohols and esters.The processing with combination of traditional drying craft and modem aroma-improvement technique could obviously improve the tea aroma,especially in level of epoxy linalool and jasmine lactone.     

Effect of Drinking Green Tea on Mental State of Humans

Tea is one of the most widely consumed beverages in the world,among which green tea is most common in China and Korea.Green tea constituents possess a great value to human health wherein lots of clinical studies and investigations were conducted by researchers and experts.However,there are still increasing demands and interest on the health properties of green tea,especially its effects on mental state of human brains.Based on the collated clinical studies,green tea was used to improve mental alertness and thinking.Thus,higher consumption of green tea was associated with a lower prevalence of cognitive impairment.This review summarizes the effects of drinking green tea on the mental state of human brains.Green tea contains a unique set of L-theanine and epigallocatechin gallate （EGCG） that possess biological activities in antioxidant,anti-memory loss,and antiproliferative assays potentially relevant to the prevention and treatment of various forms of brain damage.Theanine in green tea may play a role in reducing stress.The use of highly innovative method of reading and mental behavior of the human brain＇s response with the intake of green tea thru neuroimaging was also covered in this review.     

Advances in Preparation of Theanine

Theanine is an important component affecting tea quality and it has many health benefits for human being.Chemical synthesis of theanine had high productivity,but its application needed efficient raceme resolution technique.Although only L-theanine will be synthesized through exogenous/endogenous enzymes or microbe fermentation,low yield is the main shortage of this technique.Extraction of theanine from tea leaves is a conventional and efficient preparation technique,and highly purified theanine can be achieved when extraction and separation procedures are suitable.     

Calcium Signaling is Involved in Negative Phototropism of Rice Seminal Roots

Calcium ions （Ca2＋） act as an intracellular second messenger and affect nearly all aspects of cellular life. They are functioned by interacting with polar auxin transport, and the negative phototropism of plant roots is caused by the transport of auxin from the irradiated side to the shaded side of the roots. To clarify the role of calcium signaling in the modulation of rice root negative phototropism, as well as the relationship between polar auxin transport and calcium signaling, calcium signaling reagents were used to treat rice seminal roots which were cultivated in hydroculture and unilaterally illuminated at an intensity of 100-200 pmol/（m2.s） for 24 h. Negative phototropism curvature and growth rate of rice roots were both promoted by exogenous CaCI2 lower than 100 pmol/L, but inhibited by calcium channel blockers （verapamil and LaCI3）, calcineurin inhibitor （chlorpromazine, CPZ）, and polar auxin transport inhibitor （N-l-naphthylphthalamic acid, NPA）. Roots stopped growing and negative phototropism disappeared when the concentrations increased to 100 pmol/L verapamil, 12.500 ~Jmol/L LaCI3, 60 pmol/L CPZ, and 6 pmol/L NPA. Moreover, 100 pmol/L CaCI2 could relieve the inhibition of LaCI3, verapamil and NPA. The enhanced negative phototropism curvature was caused by the transportation of more auxin from the irradiated side to the shaded side in the presence of exogenous Ca2＋. Calcium signaling plays a key role as a second messenger in the process of light signal regulation of rice root growth and negative phototropism.     

Bacterial Community in Different Populations of Rice Brown Planthopper Nilaparvata lugens （St~l）

The structures of bacterial communities in the brown planthopper （BPH） Nilaparvata lugens （St~l） from different geographic and resistant virulent populations were analyzed by using denatured gradient gel electrophoresis （DGGE）. Results showed that the bacterial communities in BPH nymph from the first to the fifth instars varied with nymphal growth and development. The bacterial communities in the first-instar BPH nymph were similar to those in adults. Nine geographic BPH populations were divided into three groups based on the cluster analysis of DGGE fingerprint. The first group was from the Philippines; the second group was from Thailand and Hainan, Yunnan and Zhejiang provinces of China; and the third group was from Vietnam and Guangxi, Hunan and Jiangxi provinces of China. BPH populations adapted to different resistant rice varieties. The BPH populations from Mudgo （with resistant gene Bphl） and ASD7 （with resistant gene bph2） differed with those of the susceptible rice variety TNI.     

Yuexiang Longjing Tea and Its Quality Characteristics

Shengzhou is a major tea producing county in China and the major tea produced in Shengzhou is Yuexiang Longjing tea.Environment and tea cultivar are two important factors influencing tea quality.Chemical composition of tea samples prepared using materials from cultivars ‘Zhenong-117＇ and ‘ Baiye-1＇ were investigated.It showed that concentrations of total amino acids and catechins were more than 4.4％ and 129 mg/g respectively,suggesting that Yuexiang Longjing had a good quality potential.     

Studies on Bitter and Astringent Taste of Tea

Bitterness and astringency are important sensory properties for evaluating quality of tea.The research advances in the mechanism of tea astringency and bitterness,astringent and bitter tasting components and their evaluations were reviewed in the present paper.The astringency arises from the interaction of salivary proteins with polyphenols which depends on the structure of both the polyphenols and the proteins.Bitter and astringent compounds in tea include phenolic acids,catechins and their oxidized products,flavonol glycosides and proanthocyanidins.There are many factors influencing on astringency and bitterness including the interaction between taste substances,repeated ingestion,saliva flow and its composition and acidity.Sensory assessment and instrumental evaluation were used in the evaluation of astringency.