草莓果实含水量对品质的影响

将土壤水分控制在不同水平，获得了130个不同含水量的果实，分析表明：随着果实含水量的减少，果实大小、滴定酸含量降低，可溶性总糖、糖酸比、色相和硬度增加。在提高糖含量的过程中，蔗糖、葡萄糖和果糖提高的幅度并不一样，从而改变了3种单糖占可溶性总糖的比例，果实含水量与果实Brix、糖酸比的相关系数为－0.71和－0.61。     

Long-Range Transport of Sulfur from Northeast Asia to Chengshantu, Shandong Peninsula: Measurement and Simulation

Observations of air pollutants were conducted at Chengshantu in January 1996 to clarify the extent of trans-boundary pollution from the Asian continent. A nested air quality prediction modeling system (NAQPMS), which included parameters on emission, transport, diffusion, deposition and transformation of sulfur oxides, was performed to compile sulfur concentrations over the observation site. The model calculation reproduced the observed variations of sulfur oxides and sulfate well, although the model calculations could not reproduce the extensively low sulfate concentrations. Using nesting improves the ability of the modeling system to capture peak episodes seen in the observations. Calculation of the origins of deposited sulfur in each country with the NAQPMS shows that the long-range transport of sulfur is very serious. For Japan, 49% of sulfur deposition was from other countries during the campaign period.     

Characterization and in vitro culture of male germ cells from developing bovine testis

The transition from male primitive germ cells (gonocytes) to type A spermatogonia in the neonatal testis is the initial process and a crucial process in spermatogenesis. However, in large domestic animals, the physiological and biochemical characteristics of germ cells during the developmental processes remain largely unknown. In this study, we characterized bovine germ cells in the developing testis from the neonatal stage to the adult stage. The binding of the lectin Dolichos biflorus agglutinin (DBA) and the expression of ubiquitin carboxyl-terminal hydrolase 1 (UCHL1) were restricted to gonocytes in the neonatal testis and spermatogonia in the adult testis. Gonocytes also expressed a germ cell marker (VASA) and stem cell markers (NANOG and OCT3/4), while the expressions of these markers in the adult testis were restricted to differentiated spermatic cells and were rarely expressed in spermatogonia. We subsequently utilized these markers to characterize gonocytes and spermatogonia after culture in vitro. Spermatogonia that were collected from the adult testis formed colonies in vitro only for one week. On the other hand, gonocytes from the neonatal testis could proliferate and form colonies after every passage for 1.5 months in culture. These colonies retained undifferentiated states of gonocytes as confirmed by the expression of both germ cell and stem cell markers. Moreover, a transplantation assay using immunodeficient mice testes showed that long-term cultured cells derived from gonocytes were able to colonize in the recipient testis. These results indicated that bovine gonocytes could maintain germ cell and stem cell potential in vitro.     

Effects of long‐term in vitro exposure of ejaculated boar sperm to zearalenone and α‐zearalenol in sperm liquid storage medium

The effects of in vitro exposure of porcine spermatozoa to zearalenone (ZEN) and α‐zearalenol (α‐ZOL) were studied by evaluating several parameters of an in vitro fertilization (IVF) system. For this purpose, boar spermatozoa cultured with semen storage medium containing 0 (control), 10 and 1000 µg/L of ZEN and α‐ZOL for 1 week at 5°C were used for IVF of in vitro matured oocytes. Overall, there were no significant differences in the rates of total penetration, monospermic fertilization, and polyspermic fertilization of oocytes inseminated with spermatozoa from the different groups. Similarly, ZEN and α‐ZOL at 10 and 1000 µg/L did not have detrimental effects on the cleavage and development to blastocysts of oocytes after in vitro fertilization. Although the motility, viability, and plasma membrane integrity of spermatozoa significantly decreased after 3 weeks of storage compared to non‐stored spermatozoa (P < 0.05), ZEN and α‐ZOL at the evaluated concentrations did not exert detrimental effects on the above parameters, even after 3 weeks of storage. These results indicate that prolonged exposure of boar spermatozoa to ZEN and α‐ZOL up to 1000 µg/L under reduced metabolic conditions does not affect their in vitro function.     

Identification of a host 14-3-3 Protein that Interacts with Xanthomonas effector AvrRxv

AvrRxv is a member of a family of pathogen effectors present in pathogens of both plant and mammalian species. Xanthomonas campestris pv. vesicatoria strains carrying AvrRxv induce a hypersensitive response (HR) in the tomato cultivar Hawaii 7998. Using a yeast two-hybrid screen, we identified a 14-3-3 protein from tomato that interacts with AvrRxv called AvrRxv Interactor 1 (ARI1). The interaction was confirmed in vitro with affinity chromatography. Using mutagenesis, we identified a 14-3-3-binding domain in AvrRxv and demonstrated that a mutant in that domain showed concomitant loss of interaction with ARI1 and HR-inducing activity in tomato. These results demonstrate that the AvrRxv bacterial effector recruits 14-3-3 proteins for its function within host cells. AvrRxv homologues YopP and YopJ from Yersinia do not have AvrRxv-specific HR-inducing activity when delivered into tomato host cells by Agrobacterium. Although YopP itself cannot induce HR, its C-terminal domain containing the catalytic residues can replace that of AvrRxv in an AvrRxv-YopP chimera for HR-inducing activity. Phylogenetic analysis indicates that the sequences encoding the C-termini of family members are evolving independently from those encoding the N-termini. Our results support a model in which there are three functional domains in proteins of the family, translocation, interaction, and catalytic.     

Migration route of Pacific saury Cololabis saira inferred from the otolith hyaline zone

In order to establish the migration route of Pacific saury Cololabis saira, we measured the radius of otolith annual rings (ROA) in fish collected from areas off the Japanese coast up to 165°W in June and July (pre-fishing season) and from fishing grounds in August?CNovember (fishing season). The average ROA for six sea areas that each spanned 10° of longitude sampled during the pre-fishing season were compared with data obtained during each month of the fishing season. The average ROA decreased from west to east and also decreased monthly from August to November. The average ROA of fish caught after October at the peak of the fishing season was equivalent to that of the fish caught in the areas east of 160°E or 170°E. We conclude that Pacific saury caught by Japanese fishing vessels during the peak of the fishing season migrate from an area east of 160°E.     

改良荒漠化土壤的多功能高分子复合材料的制备及其应用

荒漠化土壤恢复与改良急需解决的两个关健问题是土壤保水保肥能力的提高和土壤中有植物生长所需的养分。为此,用高分子黏结剂将高吸水树脂和高分子化肥有机地结合起来,制备成多功能高分子复合材料用于沙土的改良。对多功能高分子复合材料的性能测定和应用于沙土种植试验的结果表明:在沙土中施用0.5%的多功能高分子复合材料,可提高沙地土壤的保水能力和土壤肥力,使土壤环境得到改善、种植的植物生产量获得大幅度增加。