葡萄转色成熟期管理技术措施

葡萄的转色成熟期是管理中最关键的。适当管理不仅提升今年葡萄品质、稳住产量,而且还能影响葡萄来年产量和品质。葡萄转色成熟期管理主要有六点:促转色、防裂果、防软果掉粒、防水葡萄、防干穗干尖、防病虫害。葡萄转色的本质是糖分不断累积的过程,而除遗传因素外,如光照、温度、水分、矿质元素、内源激素等均会影响其累积。本文从以下六点重点讲述,供大家参考。

辣椒果色遗传与分子生物学研究进展

综述了近年来国内外在辣椒未成熟及成熟果实颜色遗传及相关分子生物学方面取得的研究成果与进展,指出了目前辣椒果色研究中存在的问题,并对未来研究方向进行了展望。

Actin Visualization in Living Immature Pollen of Rice Using a GFP-Mouse Talin Fusion Protein

Green fluorescent protein (GFP) fused to the F_actin binding domain of mouse talin labels the actin cytoskeleton in the immature pollen of stable transformed rice (Oryza sativa L.) plants. Actin microfilaments could be visualized only in the late_developmental stage of the immature pollen. During this developmental stage, microfilaments, initially composed of very short fibrils, develop into a very complex and novel network that sometimes totally and sometimes partially encloses the vegetative nucleus and the spherical shaped generative cell in the central cytoplasm of the immature pollen. The behavior of the actin microfilamentous structure throughout the late_developmental stage of the immature pollen is extremely dynamic, and the likelihood of this structure in generating forces for vegetative nucleus and generative cell movement in the immature pollen has been discussed. No actin filaments were visualized in the spherical generative cells.

Selection of oocytes for in vitro maturation by brilliant cresyl blue staining： a study using the mouse model

Selecting oocytes that are most likely to develop is crucial for in vitro fertilization and animal cloning. Brilliant cresyl blue （BCB） staining has been used for oocyte selection in large animals, but its wider utility needs further evaluation. Mouse oocytes were divided into those stained （BCB＋） and those unstained （BCB-） according to their ooplasm BCB coloration. Chromatin configurations, cumulus cell apoptosis, cytoplasmic maturity and developmental competence were compared between the BCB＋ and BCB- oocytes. The effects of oocyte diameter, sexual maturity and gonadotropin stimulation on the competence of BCB＋ oocytes were also analyzed. In the large- and medium-size groups, BCB＋ oocytes were larger and showed more surrounded nucleoli （SN） chromatin configurations and higher frequencies of early atresia, and they also gained better cytoplasmic maturity （determined as the intracellular GSH level and pattern of mitochondrial distribution） and higher developmental potential after in vitro maturation （IVM） than the BCB-oocytes. Adult mice produced more BCB＋ oocytes with higher competence than the prepubertal mice when not primed with PMSG. PMSG priming increased both proportion and developmental potency of BCB＋ oocytes. The BCB＋ oocytes in the large-size group showed more SN chromatin configurations, better cytoplasmic maturity and higher developmental potential than their counterparts in the medium-size group. It is concluded that BCB staining can be used as an efficient method for oocyte selection, but that the competence of the BCB＋ oocytes may vary with oocyte diameter, animal sexual maturity and gonadotropin stimulation. Taken together, the series of criteria described here would allow for better choices in selecting oocytes for better development.

Mechanism of Immune Hyporesponsiveness Induced by Recipient-derived Immature Dendritic Cells in Liver Transplantation Rat

Objective To investigate the mechanism of immune hyporesponsiveness induced by donor-antigen- unloaded recipient-derived immature dendritic cell （imDC） of liver grafts in rats. Methods Forty Sprague-Dawley rats （donor） and forty male Wistar rats （recipient） were randomly divided into 4 groups： control, cyclosporine A （CsA）, mature DC （mDC）, and imDC groups respectively, with 10 donor rats and 10 recipient rats in each group. Recipient rats in CsA group were treated with 10 mg-kg-~＇d-I CsA starting day 2 after the transplantation. Recipients in the mDC or imDC groups were given Wistar rat derived mDCs （1 × 10^6/rat） or imDCs （1 × 10^6/rat） via dorsal vein of the penis respectively 1 day before the transplantation. In each group, 5 recipients were kept for determination of survival time and the other 5 rats were executed at day 10 after transplantation. Blood samples were collected for the measurement of serum alanine aminotransferase （ALT）, total bilirubin （TBIL）, interleukin 2 （IL-2）, interferon gamma （IFN-γ）, IL-4, and IL-10 levels. Liver tissue was harvested for HE staining and acute rejection evaluation. Expression levels of Fas-L/Fas in the grafts were detected by immunohistochemical staining; andWestern blot was used to detect the expression level of Scurfm. Results The survival time of CsA and imDC groups was significantly longer than that of control and mDC groups （all P〈0.05）. The levels of serum ALT and TBIL in the control group （2072.20±217.93 IU/L and 147.42±22.02pmol/L） and mDC group （2117.00±285.13 IU/L and 141.58±20.82 pmol/L） were significantly higher than those in the CsA group （59.68±13.48 IU/L and 15.40±2.13 pmol/L） or imDC group （50.80±9.63 IU/L and 14.44±3.49 pmol/L） （all P〈0.05）. In the CsA and imDC groups, the levels of IL-2 （22.52±3.75 pg/mL and 22.12±3.90 pg/mL） and IFN-γ （309.20±25.19 pg/mL and 321.00±21.64 pg/mL） were significantly lower, but the levels of IL-4 （297.60±25.07 pg/mL and 277.00±22.47 pg/mL） and IL-10 （1226.00±140.49 pg/mL and 1423.00±106.39 pg/mL） were higher than those of the control （IL-2：147.78±12.80 pg/mL, IFN-γ： 1758.60±106.22 pg/mL, IL-4：17.40±4.77pg/mL, IL-10： 81.00＋ 9.47 pg/mL） and mDC groups （IL-2：142.34±9.29 pg/mL, IFN-7：1835.00±82.63 pg/mL, IL-4： 15.60＋ 3.96 μg/mL, IL-10： 68.80± 11.23 pg/mL） （all P〈0.01）. The expression level of Scurfin protein on CD4＋CD25 ＋ T cells of the imDC group （1.34±0.29） was significantly higher than that in the control （0.72±0.13）, CsA （0.37±0.11）, and mDC groups （0.78±0.17） （all P〈0.05）.

Comparative WGBS identifies genes that influence non-ripe phenotype in tomato epimutant Colourless non-ripening

Whole-genome bisulfite sequencing(WGBS)allows single-base resolution and genome-wide profiling of DNA methylation in plants and animals.This technology provides a powerful tool to identify genes that are potentially controlled by dynamic changes of DNA methylation and demethylation.However,naturally occurring epimutants are rare and genes under epigenetic regulation as well as their biological relevances are often difficult to define.In tomato,fruit development and ripening are a complex process that involves epigenetic control.We have taken the advantage of the tomato epimutant Colourless non-ripening(Cnr)and performed comparative mining of the WGBS datasets for the Cnr and Sl CMT3-silenced Cnr fruits.We compared DNA methylation profiles for the promoter sequences of approximately 5,000 bp immediately upstream of the coding region of a list of20 genes.Differentially methylated regions were found for some of these genes.Virus-induced gene silencing(VIGS)of differentially methylated gene Sl DET1 or Sl PDS resulted in unusual brown pigmentation in Cnr fruits.These results suggest that comparative WGBS coupled with VIGS can be used to identify genes that may contribute to the colourless unripe phenotype of fruit in the Cnr epimutant.

Expression of hunchback during oogenesis and embryogenesis in Locusta migratoria manilensis(Meyen)

hb(hunchback) is a contributing factor in anteroposterior axial patterning of insects.Although the hb function in Locusta migratoria manilensis has been investigated,its expression pattern remains unknown.Here,the mouse polyclonal antibody was produced against Hb fusion protein,and then its expression pattern during oogenesis and embryogenesis of L.migratoria manilensis was examined by immunohistochemical staining.Hb protein was detected in the oocyte nucleus which was positioned centrally within the developing oocyte.The oocyte nucleus gradually moved to the posterior end of the egg along with the oocyte maturing.In freshly laid eggs,Hb formed gradient at the posterior end of the egg,and then hb was expressed as a band in the middle of the blastodisc.As the blastodisc differentiated into the head and trunk,the expression region became wide,which would develop into spatial gnathal and thoracic segments.With abdominal segmentation,the expression domain in the gnathal and thoracic region became faint and eventually faded out,while the Hb expression domain appeared at the posterior growth zone in a discontinuous expression manner.The hb expression pattern of L.migratoria manilensis is greatly similar to that of other locusts,such as Schistocerca americana and another L.migratoria.Compared with other insects,hb expression is conserved in the gnathal and thoracic domains,while divergent in oogenesis and abdomen.