Within- and between-site variations in leaf longevity in hinoki cypress (Chamaecyparis obtusa) plantations in southwestern Japan

We investigated mean leaf retention time in order to elucidate the factors affecting regional and local variations in stand-level leaf longevity in hinoki cypress (Chamaecyparis obtusa) plantations. Our study sites consisted of six stands at a low elevation (320–370 m a.s.l.) and 12 stands at a high elevation (850–970 m a.s.l.) in southwestern Japan. We also used published data on leaf longevity in stands at various elevations to clarify the regional-scale variations in leaf longevity and their relationships to environmental factors. At the regional scale, leaf longevity increased with increasing elevation and with decreasing air temperature, growing season length, and Kira’s warmth index across sites. Similar relationships were obtained for the variation in leaf mass. At the local scale, leaf longevity did not show a clear relationship with topographic position, soil water content, or soil C/N ratio. Contrary to our expectation, leaf longevity was negatively correlated with the leaf C/N ratio at both study sites, although the significance level was marginal. This indicates greater leaf longevity with better leaf nutrient status. Our results suggest that responses of leaf longevity in hinoki cypress stands to environmental factors would be more prominent at the regional scale than at the local scale, although large variation was detected at the local scale. Air temperature and growing season length appear to be the main drivers of the variation in leaf longevity at the regional scale, whereas the causal factors are unclear at the local scale.     

Roles of the zona pellucida and functional exposure of the sperm‐egg fusion factor ‘IZUMO’ during in vitro fertilization in pigs

The zona pellucida (ZP) is considered to play important roles in the prevention of polyspermy in mammalian oocytes. However, in pigs we have shown that the presence of the ZP accelerates sperm penetration into the ooplasm during in vitro fertilization (IVF). In the present study, we investigated the effects of the ZP on sperm binding, acrosomal status, and functional exposure of IZUMO, a critical factor involved in sperm‐egg fusion, during IVF in pigs. We evaluated the numbers and acrosomal statuses of sperm binding to the ZP and oolemma, and being present in the ZP and perivitelline space (PVS) using ZP‐intact and ZP‐free oocytes. More sperm bound to the ZP than to the oolemma. The average number of sperm present in the PVS was 0.44?0.51 per oocyte, and all sperm had lost their acrosomes. The proportion of sperm that were immunopositive for anti‐IZUMO antibody was significantly higher after they were passing or had passed through the ZP. Furthermore, addition of anti‐IZUMO antibody to the fertilization medium significantly inhibited the penetration of sperm into ZP‐free oocytes. These results suggest that, in pigs, the ZP induces the acrosome reaction, which is associated with the functional exposure of IZUMO, resulting in completion of fertilization.     

Effects of momilactone on the protein expression in Arabidopsis germination

Although momilactone is known to play an important role in the allelopathy of rice (Oryza sativa L.), there is no information available about the mode of action of momilactone on the allelopathy of Arabidopsis. The present research describes the allelopathic activity of momilactone A and B on the germination of Arabidopsis thaliana and the effects of momilactone A and B on protein expression during germination. Momilactone A and B inhibited the germination of Arabidopsis at concentrations >30 and 10 μmol L^?1, respectively. The protein bands of 18, 19 and 21 kDa on sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) were abundant in the momilactone A‐ and B‐treated Arabidopsis compared with the control. The protein bands of 18, 19 and 21 kDa were identified by the N‐terminal amino acid sequencing as cruciferin 2, cruciferina and cruciferin 3, respectively. Cruciferins and cruciferina are important storage proteins and play an important role as the initial source of nitrogen for seed germination. These results suggest that momilactone A and B may inhibit the germination of Arabidopsis seeds by inhibiting the degradation process of cruciferin and cruciferina.     

新疆天山野生草莓与绿色草莓(Fragaria viridis Duch.) 同一性的鉴定

 通过植物学性状观察和RAPD 技术鉴定证明新疆天山野生草莓为绿色草莓(Fragaria viridis Duch. ) , 表明中国自然分布的草莓野生种达到9 个。绿色草莓在分类学上的典型特征为匍匐茎上从第二节开始每节均形成幼苗; 花序直立、高于叶面, 花瓣显露时呈黄绿色,雄蕊花丝细长, 高于雌蕊; 果实圆形或扁圆形, 淡绿色, 阳面略红, 果硬, 成熟时萼片紧贴,脱萼难。     

Effect of centrifugation treatment before vitrification on the viability of porcine mature oocytes and zygotes produced in vitro

The aim of the present study was to investigate the effects of centrifugation pretreatment on the viability and nuclear status of porcine in vitro matured (IVM) oocytes and on the developmental competence of in vitro fertilized (IVF) oocytes (zygotes) after cryopreservation by vitrification (Solid Surface Vitrification; SSV). Mature oocytes having the first polar body after IVM and zygotes having the second polar body at 10 h after IVF were centrifuged at 10,000 x g at 37 C for 20 min and then subjected to SSV. Their viability was evaluated by morphological appearance and fluorescein diacetate staining. The nuclear status of oocytes was evaluated 6 h after vitrification. The developmental ability to the blastocyst stage of vitrified zygotes was evaluated after 6 days of in vitro culture. Although centrifugation did not damage the oocytes directly, it drastically reduced the rate of live oocytes after SSV. The rates of vitrification-induced parthenogenetic activation were similar in both centrifuged and non-centrifuged oocytes (42.4 and 47.4%, respectively). Centrifugation had no significant effects on the viability of pronuclear oocytes. The development of vitrified zygotes to the blastocyst stage was significantly lower than that of the control irrespective of centrifugation pretreatment. There was no difference in the cleavage and blastocyst rates between the control and centrifuged zygotes after vitrification. There was also no difference in the total cell numbers of blastocysts between the control and centrifuged zygotes irrespective of vitrification. These results reveal that, in IVM porcine oocytes, centrifugation pretreatment is highly detrimental to cryotolerance; however, in zygotes, it has only a slight effect on viability and does not alter the developmental competence of surviving zygotes.     

Cover Image,Volume 14, Issue 4

The cover image, by Shunsuke Noguchi et al., is based on the Original Article Analysis of microRNA‐203 function in CREB/MITF/RAB27a pathway: comparison between canine and human melanoma cells, DOI: 10.1111/vco.12118 .

     

Protective effect of ubiquinone (coenzyme Q9) on ascites in broiler chickens

1. The effect of ubiquinone (C0Q9) on ascites in broiler chickens was investigated.

2. The commercial broilers were divided into 2 groups of 100 birds each; CoQ9‐treated group and non‐treated group.

3. The chickens were grown in a positive‐pressured house with double high efficiency particulate air filtered intakes and exhaust, and thus were strictly isolated from infectious agents.

4. The chickens (15 to 21 d old) were exposed to cold stress in order to induce ascites.

5. The number of birds with ascites in the C0Q3‐treated group was significantly lower than in the non‐treated group.

6. Survival and production rates were better in the CoQ^‐treated group than in the non‐treated group.     

Pasting Characteristics of Maize Starch Heat‐Treated with Different Water‐Ethanol Mixtures

Pasting characteristics of maize starch heat‐treated with six different water‐to‐ethanol ratios (%wt base 0:100, 10:90, 20:80, 30:70, 40:60, 50:50) were investigated; treated starches were called EW 0, 10, 20, 30, 40, and 50, respectively. Endotherms in DSC analysis shifted to a higher temperature as the water content in water‐ethanol mixture increased. The removed amount of fatty acids was much higher in treatments for EW 10, 20, and 30. The RVA peak viscosity of EW 10 and 20 were highest among the treated starches and setbacks were more than twice that of untreated starch. The characteristic change in the RVA viscogram corresponded to the amount of leached amylose from the granule. EW 30 displays similar properties as conventional heat‐moisture‐treated starch, but maintained a higher viscosity of ≈300 RVU throughout the heating process. In treatment with water‐ethanol mixtures, heat‐moisture treatment and defatting effects generated new types of modified starches. EW 40 and 50 had no clear pasting peak on RVA, and showed a viscosity at low temperature similar to granular cold water gelling.     

Estimation of fine root biomass using a minirhizotron technique among three vegetation types in a cool-temperate brackish marsh

The minirhizotron technique is a non-destructive method to evaluate fine roots, which converts two-dimensional image data to three- dimensional root biomass data. Recently, conversion factors in soils at 10-cm depth intervals successfully estimated fine root biomass using image data from the minirhizotron method. However, this technique was conducted only at one forest site and did not consider different vegetation types. Therefore, the objective of this study was to verify a method for calibration of minirhizotron data with the core sampling values obtained by direct measurement of root biomass in wetland ecosystems among three vegetation types. Evaluations by minirhizotron technique and soil-core sampling were made at 30-cm soil depth in a cool-temperate brackish marsh in northern Japan. Linear regression was examined between root volume and weight of fine roots in soil core samples, and the fine root biomass on minirhizotron tubes was calculated from their length and diameter. The technique was well adapted for vegetation types dominated by Phragmites australis, Juncus yokoscensis, and Miscanthus sinensis and Cirsium inundatum. Compared with the fine root biomass estimated by the core sampling method, fine root biomass estimated by the minirhizotron method was overestimated in the 0–10-cm layer. Further, we determined conversion factors based on the ratio of the fine root biomass by the core sampling method to that by the minirhizotron tubes. Estimation of the fine root biomass using the conversion factors for each 10-cm soil depth was well adapted in P. australis vegetation and J. yokoscensis vegetation types as a forest ecosystem; meanwhile, M. sinensis and C. inundatum vegetation types were not well adapted. This study suggests that the minirhizotron technique is available to estimate fine root biomass of single-species dominated vegetation in the brackish marsh using conversion factors for each 10-cm depth.