Mar 2008, Volume 2 Issue 1

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  • LIU Diqiu, ZHANG Xianlong
    Cotton is the most important natural fiber plant in the world. The genetic improvement of the quality of the cotton fiber and agricultural productivity is imperative under the situation of increasing consumption and rapid development of textile technology. Recently, the study of cotton molecular biology has progressed greatly. A lot of specifically or preferentially expressed cotton fiber genes were cloned and analyzed. On the other hand, identification of stress response genes expressed in cotton was performed by other research groups. The major stress factors were studied including the wilt pathogens Verticillium dahliae, Fusarium oxysporum f. sp. vasinfectum, bacterial blight, root-knot nematode, drought, and salt stress. What is more, a few genes related to the biosynthesis of gossypol, other sesquiterpene phytoalexins and the major seed oil fatty acids were isolated from cotton. In the present review, we focused on the major advances in cotton gene cloning and expression profiling in the recent years.
  • PAN Zhifen, ZOU Yixing, ZHAO Tao, ZHAI Xuguang, WU Fang, DENG Guangbing, YU Maoqun
    Starch granule proteins (SGPs) are minor components bound with starch granule, whose variation could impact starch properties. This study investigated, for the first time, the variation of SGPs in the cultivated naked barley from Qinghai-Tibet Plateau in China. The relationship between SGPs and starch content was preliminarily dealt with. Ten major SGPs and 16 types of patterns were present in the 66 cultivated naked varieties, indicating that the SGPs in cultivated naked barley from Qinghai-Tibet Plateau in China are polymorphic. The SGPs of naked barley in Tibet and Sichuan were greatly different and the SGP patterns were specific to sampling regions. Significance test analysis demonstrated that the SGPs described in this study, except for SGP1, could be related with the variation of starch content in the different naked barleys.
  • LONG Wenbo, LUAN Li, WANG Xing, LIU Yuhua, TU Shengbin, KONG Fanlun, HE Tao
    Cytogenetical comparison was made between high seed setting restorers TP-4 and Dminghui63 with eminent maintainer line D46B of autotetraploid rice. The meiosis observation demonstrated that the genomes of our autotetraploid materials were all 2n = 48, which was the same as those in mitosis observation. Low percentages of univalent and trivalent in diakinesis-metaphase I (MI) of restorers TP-4 and Dminghui63 as well as maintainer line D46B of autotetraploid rice were observed. And the percentages of chromosome pairing were all over 99%, showing eminent cytological character. The frequency of TP-4 and Dminghui63 in diakinesis-metaphase I was 2.00/PMC (pollen mother cell) and 2.26/PMC, respectively. However, the frequency of D46B was 6.00/PMC, significantly higher than those of TP-4 and Dminghui63. It indicated that the maintainer D46B had better chromosome pairing capability in diakinesis-metaphase. While, the frequency of lagging chromosomes of the maintainer D46B in anaphase I (AI) was 10.62%, significantly lower than that of TP-4 (19.44%) or Dminghui63 (23.14%), and close to the level of diploid control (7.30%). In telophase I (TI), maintainer D46B exhibited lower frequency of microkernel, and in telophase II (TII) the frequency of normal quartered microspore of maintainer D46B was not only higher than that of TP-4 or Dminghui63 but also than that of diploid control. The percentage of the cell observed chromosome lagging in AI and the percentage of abnormal cell in TI showed a greatly significant positive correlation. That may demonstrate that chromosome separation in AI and microkernel formation in TI are controlled by the same dominant single gene or the major gene of a QTL.
  • XU Hai, LIU Hongguang, ZHU Chunjie, GUO Yanhua, WANG Jiayu, XU Zhengjin, CHEN Wenfu, YANG Li, YANG Qianhua, ZHENG Jiakui
    Two recombinant inbred lines (RILs) populations, RILSA derived from the cross between “Zhongyouzao8” (indica) and “Toyonihiki” (japonica) rice cultivars, and RILSB derived from the cross between “Qishanzhan” (indica) and “Akihikari” (japonica) rice cultivars, were grown in Liaoning and Sichuan Provinces, China to understand the effects of ecological environments on the subspecies characteristics and economic traits in filial generations of cross between indica and japonica. The results showed that both the subspecies characteristics and economic traits changed significantly. The effects of ecological environments on Cheng’s index and six subspecies characteristics were different on the basis of populations or characteristics. The distribution of Cheng’s index in RILSA was japonicalinous in Liaoning and Sichuan. The distribution of Cheng’s index in RILSB approached to normal distribution in Liaoning, but it was japonicalinous in Sichuan. As a whole, the two populations were more japonicalious in Sichuan than in Liaoning. The panicle number, seed setting rate and per-thousand-grain weight were decreased significantly in Sichuan. The grain number per panicle showed no significant change. A significant positive correlation was found between Cheng’s index and the economic traits, including six subspecies traits. It suggested that the reason that the filial generation of cross between indica and japonica in northern China showed japonicanous subspecies characteristics might be the artificial selection by breeders on the economic traits. In addition, indica-japonica differentiation and the relationship with ecological environments were discussed.
  • GUO Li, WANG Jiaojiao, XIAO Kai
    A novel phytase gene Sphy1 was isolated based on screening a cDNA library which was constructed from germinated soybean (Glycine max (L.) Merr. cv. Kefeng 6) cotyledon. The full-length cDNA of Sphy1 was 1644 bp predicated to encode 547 amino acids including an N terminal signal peptide of 27 amino acids. Phylogenetic analysis indicated that Sphy1 had high similarities with the phytase genes from Medicago truncatula and rice, and acid phosphatase genes from M. truncatula and Arabidopsis. Prokaryotic expression of Sphy1 in Escherichia coli BL21 (DE3) showed that the induced protein had high phytase activities. The transcripts of Sphy1 could be detected in various tissues, such as cotyledons, leaves, stems and roots of seedlings. The phytase activities in the above tissues were in accordance with their corresponding Sphy1 transcripts. The transcripts of Sphy1 in cotyledons showed an increasing trend from 5 to 30 days after germination, suggesting that Sphy1 had involved the hydrolyses of the organic phosphorus compounds in seeds from the stages of early seed germination to young seedlings in soybean. Therefore, it was speculated that Sphy1 played an important role during the seed germination and the growth of the seedlings by releasing inorganic phosphorus (Pi) from phosphorus reserve in seeds.
  • SUN Qingquan, DONG Shuting, ZHANG Chunqing, ZHANG Ying, MA Dengchao
    The efficient acceptors for maize transgenic engineering are currently insufficient in China. Seed production by male sterility is the best method for advancing the authenticity of maize hybrid. Maize inbred line 18-599 (white) is an antivirus high-quality maize inbred line in China, which has been used for lots of maize hybrid cultivars. The establishment of high efficiency transgenic acceptors is necessary for advancing the transgenic efficiency in maize transformation work. In this study, the efficient transgenic acceptors were optimized and established. 18-599 (white) was studied in state, types of culture mediums, times of callus regeneration and concentration of the screening reagent, Basta. The results showed that N6-4 medium was the best in 8 types of mediums for the immature embryo of 18-599 (white), 1.6 mm length was the feasible length of immature embryos for tissue culture in establishing the transgenic acceptor system, and it was within 5 times for suitable callus subculture. With the optimized transgenic acceptors, barnase gene was translated successfully into 18-599 (white) by a particle gun using bar as a marker gene. Basta was used as the screening reagent, its lethal concentration was 8 mg·L-1 and its working concentration for screening was 6, 8 and 6 mg·L-1 in 3 turns for callus regeneration, respectively. In this work, a transgenic plant with male sterility was obtained through molecule detection and observation in the field. The result has an important significance for the creation of new male sterility inbred lines in maize in the future.
  • YI Zhenxie, WANG Pu, TAO Hongbin, ZHANG Hongfang, SHEN Lixia
    To reduce nitrogen fertilizer (NF) loss and improve nitrogen use efficiency (NUE) in summer maize, the effects of the different application rates of three types of NF (urea, coated urea and compound fertilizer) on the growth and development and NUE of summer maize (cultivars: Zhengdan958 and Nongda108) were studied in 2004. The main findings of this study were: (1) The yields of the two cultivars increased significantly with each increment of N application rate from 0–180 kg N·hm-2. The increase in the yield of summer maize treated with compound fertilizer was greater than the yield of those treated with either of the other two fertilizers at the same application rate, while the differences among the three types of NF were not significant. (2) Grain number per ear of the two cultivars rose in relation to the increase in N application rate, while its relationship with the type of NF was very weak. The type of NF had a greater impact on 1000-grain weight, and a difference between cultivars was observed. (3) Leaf area index (LAI), dry matter weight and leaf chlorophyll content grew in relation to the increase in N application rate, and were improved more sharply by compound fertilizer or coated urea than by urea alone. (4) Compared to the results achieved with urea, the NUEs of summer maize treated with coated urea and compound fertilizer were higher but the nitrogen harvest index was not improved. In addition, the NUEs of three types of NF exhibited a genotype difference from summer maize.
  • FANG Zheng, AN Zhenfeng, LI Yingli
    Through solution culture experiment and liquid chromatogram technique, two wheat (Triticum aestivum L.) genotypes with different tolerances to Mn deficiency were used to study the dynamic change of organic acids secreted from wheat root in the conditions of no Mn, low Mn and normal Mn supply. Nine kinds of organic acids were measured in wheat root exudate. The results showed that there were significant differences of organic acids in root exudate between tolerant genotype and susceptible genotype under Mn-stressed conditions. Tolerant genotype 9023 secreted more organic acids from the plant roots than susceptible genotype CM28. The main organic acid exudate included tartaric acid, malic acid, acetic acid, maleic acid and fumaric acid. Of all these acids, the amounts of tartaric acid and malic acid in root exudate showed significant differences between the tolerant genotype and susceptible genotype under Mn-stressed conditions. The results also indicated that secreting organic acids into root rhizosphere was an active response to Mn deficiency for the tolerant genotype of wheat.
  • WANG Tian, WANG Suping, GUO Shirong, SUN Yanjun
    With water culture, this paper studied the effects of exogenous spermidine (Spd) on the net photosynthetic rate (Pn), intercellular CO2 concentrations (Ci), stomatal conductance (Gs), transpiration rate (Tr), apparent quantum yield (?c), and carboxylation efficiency (CE) of cucumber seedlings under hypoxia stress. The results showed that Pn decreased gradually under the hypoxia stress, and reached the minimum 10 days later, which was 63.33% of the control. Compared with that of the hypoxia-stressed plants, the Pn 10 days after the application of exogenous Spd increased by 1.25 times. A negative correlation (R2 = 0.473–0.7118) was found between Pn and Ci, and Gs and Tr changed in wider ranges, which decreased under the hypoxia-stress, but increased under the hypoxia-stress plus exogenous Spd application. There was a significant positive correlation between Gs and Tr (R2 = 0.7821–0.9458), but these two parameters had no significant correlation with Pn. The hypoxia stress induced a decrease of ?c and CE by 63.01% and 72.33%, respectively, while the hypoxia stress plus exogenous Spd application made ?c and CE increase by 23% and 14%, respectively. The photo-inhibition of cucumber seedlings under hypoxia stress was mainly caused by non-stomatal inhibition, while the exogenous Spd alleviating the hypoxia stress by repairing photosynthesis systems.
  • HUANG Benli, XU Yundong, WU Ye, ZHANG Shunqi, CHEN Xuehao
    This study investigated the effect of root exudates of cucumber varieties, Jinyan 4 (susceptible variety), Jinchun 4 (resistant variety) and Yinnan Black seed squash on fusarium wilt. The results showed that fusarium wilt occurrence of plants treated with the root exudate of Jinyan 4 was earlier. The infection rate was significantly higher 15 days after inoculation, but similar to the control 20 days after inoculation. In contrast, the infection rate of plants treated with the root exudate of Jinchun 4 was significantly lower than that of the control. The plant height and fresh weight of Jinyan 4 treated with its own root exudate were lower than those of the control, and the root vigor decreased but the conductance increased. There was no significant effect of the root exudates from Jinchun 4 and Black seed squash on plant height and fresh mass of Jinyan 4. We found that the root exudate of susceptible cucumber variety stimulated the growth of Fusarium oxysporum pathogen, in contrast, that of resistance variety and Black seed squash suppressed the growth.
  • LIU Xuemin, ZHOU Yanling, LI Lijun
    Under controlled conditions in a growth chamber, we studied the mortality of pepper seedlings caused by Phytophthora capsici. The results showed that soil temperature and soil water content were important factors affecting their infection with P. capsici and the optimum condition for infection was found to be a soil temperature of 22°C–28°C and a soil water content of 40%. The relationships of pepper seedling mortality caused by P. capsici along with soil temperature, soil water content and their interactions can be described by mathematical models. Field observations suggested that the Gompertz model was the best one for describing the epidemiological dynamics of the disease. The incidence of pepper phytophthora blight was significantly related to the initial incidence of pepper phytophthora blight, soil temperature, soil water content and air temperature. A forecasting model for pepper phytophthora blight in the field was developed.
  • ZHANG Yu, HU Tongle, JI Lijing, CAO Keqiang
    Pre-plant soil fumigation with methyl bromide (MB) is a standard practice for controlling soil-borne diseases especially for strawberry diseases. However, the application of MB will be forbidden in China in the year 2015. For this reason, a bio-product named Kangdi 3 was tested as an alternative to MB in strawberry greenhouses in Mancheng (Hebei Province) and Donggang (Liaoning province), China in 2005 and 2006. Methyl bromide at a normal dosage of 500 kg/hm2 and Kangdi 3 at three dosages of 750, 1500 and 2250 kg/hm2 were tested. Plots without any treatment were used as the control. During the growing stage, assessments were made on fungal communities in rhizosphere, growth status of strawberry, the disease levels on roots as well as the yields. Results showed that Kangdi 3 significantly reduced the quantity of fungi and the disease index, while enhancing strawberry growth and the yields compared with the untreated control. Therefore, Kangdi 3 is a great potential substitute for methyl bromide to control replant diseases in strawberry.
  • LI Xiaodong, ZHENG Xianbo, YAN Shutang
    Effects of salicylic acid (SA), ultraviolet radiation (UV-B and UV-C) on the trans-resveratrol (Res) inducement of the skin of harvested grape berries were studied with three grape cultivars Takasuma, Tano Red and Carigane. Split plot design tests were adopted to compare the effects of UV-B and UV-C radiation on Res inducement of different cultivars. Results showed that spraying 100 mg·L-1 SA markedly enhanced Res contents in the skins of harvested berries for the three selected cultivars. However, the effect of SA varied with the cultivars, and Res inducement by SA was more effective to Tano Red than Takasuma and Carigane. UV-B or UV-C irradiation significantly increased Res contents in grape skins and UV-C was more effective than UV-B. The effects of UV types and dosages on Res inducement depended upon cultivars. In the range of 0–3.6 kJ·m-2, the Res contents in the skins of the three grape cultivars were enhanced along with the increase of dosages of UV-B and UV-C.
  • ZHANG Yuxing, DU Guoqiang, POUDYAL Bharat Kumar
    The pear (Pyrus spp.) is one of the most important temperate fruit crops. A complete protocol for adventitious shoot regeneration was developed from the leaves of four pear varieties grown in vitro: Abbe Fetel, Yali, Packham’s Triumph and Aikansui, and the Chinese rootstock variety Duli. Shoot explants were collected from the field and cultured in vitro in Murashige and Skoog (MS) media supplemented with 1.0 mg·L-1 6-benzylaminopurine (BA) and 0.1 mg·L-1 indole-3-butyric acid (IBA). After four weeks, leaf explants of all 5 varieties grown in vitro were excised and cultured in MS media supplemented with 0.0 mg·L-1, 0.2 mg·L-1, 0.5 mg·L-1, 1.0 mg·L-1 and 2.0 mg·L-1 naphthaleneacetic acid (NAA) and 5.0 mg·L-1 BA or with 1.0 mg·L-1, 2.0 mg·L-1 and 4.0 mg·L-1 thidiazuron (TDZ). The cultures were maintained in darkness for 21 days for shoot induction in the shoot induction medium (IM), then transferred to the shoot expression medium (EM) in 1.0 mg·L-1 TDZ without any auxins and kept in a growth room at (25 ± 2)°C under a 16/8 h light/dark photoperiod regime for 8 weeks. Finally, the shoots were transferred to the MS shoot elongation medium (SEM) supplemented with 0.2 mg·L-1 BA, 0.1 mg·L-1 IBA and 0.2 mg·L-1 gibberellic acid (GA3). A combination of TDZ and NAA had a significant effect on the number of shoot regenerations in all 5 tested varieties. The maximum mean number of shoots and maximum number of shoots per leaf obtained from Yali variety were 11.8 (P ≤ 0.001) and 22, followed by Aikansui with 6.6 (P ≤ 0.001) and 4.6, and Duli with 8 (P ≤ 0.001) and 12, all arising from the combination of 0.2 mg·L-1 NAA with 1.0 mg·L-1 TDZ. For Packham’s Triumph and Abbe Fetel, the maximum mean number of shoots and maximum number of shoots per leaf were 5.6 (P ≤ 0.001), 4.8 and 8 (P ≤ 0.001), and 11, respectively, from the combination of NAA (1.0 mg·L-1) and TDZ (2.0 mg·L-1). Abbe Fetel was the only variety which produced significantly higher adventitious shoots from the two different combinations of 1.0 mg·L-1 NAA and 5.0 mg·L-1 BA (P ≤ 0.05), and 2.0 mg·L-1 NAA and 5.0 mg·L-1 BA (P ≤ 0.01). Some of the most prominent problems associated with shoot proliferation and regeneration were also observed and discussed in this paper.
  • HAN Mingyu, LI Bingzhi, ZHANG Linsen, BAI Ru, Gao Dengtao
    The effect of different modified tree shapes (MTS) on light reception was compared among three types of apple orchards: small-sized canopy, middle-sized canopy and large-sized canopy in Weibei areas of Shaanxi Province, China, by using WinsCanopy2004a (2002) for Hemispherical Image Analysis. The results showed that higher average values of photosynthetic photon flux density (PPFD) under canopy per day appeared in all tested orchards, and the number of branches per 667 m2 was lower, indicating that the modified tree shapes were effective to improve the light conditions of canopy but the pruning amount seemed to be slightly more than the appropriate level in Weibei areas. The middle-sized canopy had the maximal light penetration and the small-sized canopy had the least and the leaf area index (LAI) and the ratio of one year-old shoots to scaffold limbs were maximal in large-sized canopy orchards.
  • ZHANG Jianguang, CHEN Shaochun, DI Bao, ZHANG Jianqiang, LIU Yufang, LI Yingli
    The present experiment was conducted to examine the changing patterns of glutathione (GSH) contents in apple peel stressed by high temperature and excessive solar radiation. By comparing the parameters of temperature and light conditions where fruits grow with the GSH contents in them, the mutual relationship was disclosed. Meanwhile, the changes of antioxidant capacity of fruits stressed at different levels were studied under artificially controlled conditions in a laboratory. Also, the effect of applying various types of exogenous substances was evaluated on endogenous GSH contents. The results indicated that within a certain range, a positive correlation was found between the stressed extents to which fruits were subject by high temperature and excessive light, and GSH contents in fruit peel. Moreover, fruits on southwest (SW) exposure contained a very significantly higher amount of GSH than those on other exposures. In laboratory experiments, it was proved that fruit GSH contents increased with temperatures within a certain range but they declined beyond a given limit. The temperature rising modes had a great influence on fruit GSH contents, and gradual temperature increase was favorable to an increase of antioxidant capability in fruit peel, thus providing a theoretical basis for exerting appropriate acclimation on fruits. It was also documented that application of four exogenous formulations could significantly increase the endogenous GSH contents, among which AsA (ascorbit acid) + BA (benzoic acid) and SA (salicylic acid) treatments exhibited better results, 33.97% and 31.81% higher than the control, respectively.
  • LI Xianglong, ZHOU Rongyan, ZHENG Guiru, LI Lanhui, LIU Zhengzhu, GONG Yuanfang
    A total of 436 goat samples from twenty-six populations were scanned for single nucleotide polymorphisms (SNPs) in 5′UTR of goat MSTN gene using sequencing and the polymerase chain reaction technique combined with restriction enzyme fragment length polymorphism (PCR-RFLP). The deletion of TTTTA found in 5′UTR of goat MSTN gene was conserved in different species and might be a unique mutation in goats. The Foreign Group and the Boer Goat backcrossed offspring had the highest and smallest genetic diversity of this mutation respectively, and also with the smallest and highest heterozygosity deficiency respectively. The genetic diversity of this mutation for the South Group of Chinese indigenous goat breeds was higher than that of the North Group, and the South Group had the smaller heterozygosity deficiency than the North Group. The estimated marginal means based on the modified population marginal mean and pairwise comparison between significant pairs showed that there was a trend that genotype AA had a significant effect on body weight and size from birth to four-month old (P < 0.05 or P < 0.01). It could be inferred that the deletion of TTTTA in 5′UTR of goat MSTN gene had a significant effect on body weight and size.
  • LIU Wenkui, FAN Qixue, ZHU Bangke, DU Haiming, FENG Xigang
    The effects of prey density (0.1, 0.3, 1, 3 and 10 prey·mL-1) on the growth and survival of hybrid snakehead (Channa argus × C. maculate) larvae were investigated. The larvae were divided into three groups with different body lengths of 0.68 cm, 1.50 cm and 3.20 cm, respectively. The growth of the hybrid snakehead larvae in all three groups increased with prey density increasing from 0.1 to 1 prey·mL-1. The specific growth rate (SGR) was the highest when the prey density was 1 prey·mL-1. When prey density was higher than 1 prey·mL-1, SGR of larvae in Group I (the larvae of early development stage) decreased, while no significant change was observed in those of Group II and Group III. The survival rates of hybrid snakehead larvae in all three groups were high (91.11%–100%) and not significantly affected by the prey densities except in Group I with the highest prey density (10.0 prey·mL-1) which was significantly lower than the others. Body size was not sensitive to prey density. The optimum prey density was confirmed at 1 prey·mL-1 in all the treatments.
  • WANG Jiaxin, BIAN Haixia, SHI Wei, LU Zhanjun
    Dendritic cells (DCs) are professional antigen-presenting cells. However, the distribution of bovine DCs in the pharynx, tonsil, and retropharyngeal lymph nodes has not yet been documented. To address this issue, immunohistochemistry was conducted using S-100 protein as a marker for DCs. It was observed that S-100 positive Langerhans cells (LCs) were primarily found in the basal layer of the pharyngeal epithelium. Some DCs were found in the outer layer of the epithelium and their dendrites extended out towards the epithelial surface. In the tonsil, S-100 positive DCs were found either in follicular germinal centers or in the T-cell areas. It is worth noting that the S-100 positive DCs were not only distributed in the cortex, but also in the medulla of bovine retropharyngeal lymph nodes. The distribution patterns of bovine DCs in the pharynx, tonsil, and retropharyngeal lymph nodes have an important implication for our understanding of the interaction between pathogens and host.
  • JIA Wenbin, LI Qiufeng, GAO Yanxia, LI Jianguo, CAO Yufeng
    Eight Chinese Holstein cows were used in a 4 × 4 Latin square design to determine the effects of rumen protected methionine (RPMet) and Niacin on milk yield and milk composition of lactating cows with 14 d adaptation and 6-d sampling periods. The cows were fed the control diet or the control diet plus RPMet (25 g·d-1), niacin (6 g·d-1), or RPMet (25 g·d-1) + niacin (6 g·d-1). The results showed that RPMet supplementation in the diet increased 4% fat corrected milk (FCM) yield (P < 0.05) and milk fat percentage (P < 0.05). However, supplemental RPMet had no effect on the solid non fat (SNF) (P > 0.05) and lactose percentage (P > 0.05). Dietary niacin supplementation increased milk yield (P < 0.05), milk protein percentage (P < 0.05) and lactose percentage (P < 0.05), but had no effect on milk fat percentage (P > 0.05) and SNF (P > 0.05). RPMet supplementation in the diet of lactating cows significantly decreased serum urea nitrogen (P < 0.01) and glucose contents (P < 0.05), but had no effects on nonesterified fatty acids (NEFA), total cholesterol and triglyceride (P > 0.05). Niacin supplementation influenced the contents of glucose and NEFA in serum, but had no effects on the urea nitrogen, total cholesterol and triglyceride (P > 0.05).