《隐入尘烟》:多维的互文性表述

电影《隐入尘烟》在上映五十多天后,奇迹般地连续数日制霸单日票房榜榜首,并于2022年9月7日总票房突破一亿大关。影片的现象级表现建立在文本与多个维度的互文性表述之上。新媒体语境下的多种文本生产样式与原片形成了跨媒介互文,尤其是短视频平台的文本共创有效推动了影片的口碑发酵。同时导演关于对生命轮回的思考、对土地的情感依恋以及对农村文明与乡村文明二元对立的表述与当下的社会文化变迁形成了互文关联,从而引发诸多观众的情感共鸣。此外,影片作为一部现实主义力作,作者身份投射的痕迹尤为明显,使得家乡叙事与作者身份建构起一种统一性,同时也与当代大众多元的身份与文化记忆形成了互文,助力了影片实现长尾效应,为文艺电影有效出圈打开了可能性空间。

杜梨对盐碱胁迫的生理响应及耐盐碱性评价

为探究不同杜梨资源对盐碱胁迫的生理响应及筛选耐盐碱资源,以甘肃、山西、辽宁等地收集的17份杜梨资源3000余株幼苗为试验材料,采用中性盐和碱性盐混合胁迫处理,测定盐碱抗性相关的生理指标,基于主成分分析法、热图及聚类分析法和抗逆系数法进行抗性评价。研究发现,抗性强的资源抗氧化酶活性和脯氨酸含量在受到胁迫后显著上升,300 mmol/L盐碱胁迫下超氧化物歧化酶活性显著上升的资源为河底杜梨3和平陆杜梨1,分别上升了75.04%、70.04%;过氧化物酶活性上升显著的资源为甘肃杜梨1和河底杜梨1,分别上升了1136.11%、742.86%;过氧化氢酶活性显著上升的资源为甘肃杜梨15、甘肃杜梨4,分别上升了344.58%、343.42%,脯氨酸含量显著上升的资源为平陆杜梨2、河底杜梨1、河底杜梨3,丙二醛含量上升较多的资源为甘肃杜梨16、甘肃杜梨13、甘肃杜梨1。除甘肃杜梨13在低浓度(100 mmol/L)盐碱胁迫即出现明显盐害现象外,其他杜梨资源均在300 mmol/L浓度处理下才开始出现不同程度的盐害;利用不同方法进行耐盐碱性分析结果存在一定的差异,其中基于主成分分析法发现河底杜梨1、河底杜梨3、平陆杜梨1、甘肃杜梨15、山西杜梨1耐盐碱性强;基于热图和聚类分析发现甘肃杜梨4、甘肃杜梨15、平陆杜梨1、河底杜梨1和河底杜梨3具有较强的耐盐碱性;而利用抗逆系数法分析耐盐碱性较强的资源为甘肃杜梨1、河底杜梨1、甘肃杜梨16、甘肃杜梨4、甘肃杜梨15。综合3种方法的分析结果,河底杜梨1和甘肃杜梨15属于高抗盐碱类型,而甘肃杜梨13则为盐碱敏感型资源。

An assessment of the genetic diversity of pear(Pyrus L.)germplasm resources based on the fruit phenotypic traits

Germplasm resources are an important basis for genetic breeding and analysis of complex traits,and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.In this study,the distribution frequency,coefficient of variation,Shannon-Wiener index,and variance and cluster analyses were used to analyze the diversity and trait differences of 39 fruit phenotypic traits from 570 pear accessions,which included 456 pear accessions from 11 species and 114 interspecific hybrid cultivars that had been stored in the National Germplasm Repository of Apple and Pear(Xingcheng,China).The comprehensive evaluation indices were screened by correlation,principal component and regression analyses.A total of 132 variant types were detected in 28 categorical traits of pear germplasm fruit,which indicate a rich diversity.The diversity indices in decreasing order were:fruit shape(1.949),attitude of calyx(1.908),flesh texture type(1.700),persistency of calyx(1.681),russet location(1.658),relief of area around eye basin(1.644),flavor(1.610)and ground color(1.592).The coefficient of variation of titratable acidity in the 11 numerical traits of pear germplasm fruit was as high as 128.43%,which could more effectively reflect the differences between pear accessions.The phenotypic differentiation coefficient V_(st)(66.4%)among the five cultivated pear species,including Pyrus bretschneideri(White Pear),P.pyrifolia(Sand Pear),P.ussuriensis(Ussurian Pear),P.sinkiangensis(Xinjiang Pear),and P.communis(European Pear),was higher than the within population phenotypic differentiation coefficient V_(st)(33.6%).The variation among populations was the main source of variation in pear fruit traits.A hierarchical cluster analysis divided the 389 accessions of six cultivated pear species,including P.pashia(Himalayan Pear),into six categories.There were certain characteristics within the populations,and the differences between populations were not completely clustered by region.For example,Sand Pear cultivars from Japan and the Korean Peninsula clustered together with those from China.Most of the White Pear cultivars clustered with the Sand Pear,and a few clustered with the Ussurian Pear cultivars.The Ussurian Pear and European Pear cultivars clustered separately.The Xinjiang Pear and Himalayan Pear did not cluster together,and neither did the cultivars.Seventeen traits,three describing fruit weight and edible rate(fruit diameter,fruit length and fruit core size),five describing outer quality and morphological characteristics(over color,amount of russeting,dot obviousness,fruit shape,and stalk length),and nine describing inner quality(flesh color,juiciness of flesh,aroma,flavor,flesh texture,flesh texture type,soluble solid contents,titratable acidity,and eating quality)were selected from the 39 traits by principal component and stepwise regression analyses.These 17 traits could reflect 99.3%of the total variation and can be used as a comprehensive evaluation index for pear germplasm resources.

不同气候情景下木梨潜在地理分布格局变化的预测

木梨的抗旱、抗寒、抗盐碱和抗梨锈病的能力较强,是我国西北地区梨的主要砧木类型之一,具有较高的生产价值。但目前其生境破坏较为严重。预测不同气候情景下木梨的地理分布可为木梨资源的合理开发利用及多样性保护提供重要的科学依据。本研究利用木梨全面且精确的分布信息和高分辨率环境数据,基于MaxEnt模型和ArcGIS空间分析,构建其当代及未来(2050和2070年)的潜在空间分布格局,评价环境因子对分布模型的重要性。结果表明:目前木梨适宜生境面积为33.2万km2,主要位于我国青海东部、甘肃南部、宁夏南部、陕西中部、山西南部和河南西部地区,紫外线辐射量最少月份的平均紫外线量和海拔是限制其分布的主要环境因子。随着全球气候变暖,在不同CO2浓度情景下,2050和2070年木梨的潜在适生境将逐渐减少,应加强对木梨群体的实时监测。