海南部分荔枝种质的ISSR分析

从74条引物中筛选出23条多态性引物,用ISSR方法对80份海南荔枝(Litchi chinensis Sonn)种质进行分子标记分析和遗传多样性研究。结果表明,大多数种质的遗传距离在0.2￣0.5之间,说明它们的亲缘关系较近。在遗传距离为0.55的水平上,80份荔枝种质被分为7组,海垦8号、琼山3号与永25单独为一组,可能属于海南的地方种质。另外,通过与SSR,RAPD等方法对比,ISSR方法应用前景较好。     

海南荔枝种质资源果实主要性状多样性分析

对中国热带农业科学院热带作物品种资源研究所、海南省农业科学院热带果树研究所种质圃的荔枝品种（种质）和海南的霸王岭、尖峰岭等地采集的野生荔枝果实的主要性状进行了鉴定评价。结果表明：海南荔枝品种（种质）的果实形状、果实大小、果皮龟裂片、果皮颜色、果实可食率、可溶性固形物、可滴定酸、维生素C含量等方面均存在丰富的遗传多样性。     

不同海南荔枝品种果实采后生理及品质变化的比较研究

以‘紫娘喜’等6个海南主栽荔枝品种为试材,研究了果实采后贮藏过程中品质变化,结果表明:果实贮藏期间,6个品种的果实果皮褐变指数快速上升,好果率下降,同时,果皮失水率和pH值上升,果皮花色苷含量下降。无核荔枝果皮褐变最快,而紫娘喜果皮褐变最慢,主要与果皮失水速率有关。贮藏过程中供试品种果肉可溶性固形物(TSS)、可滴定酸(TA)和抗坏血酸(Vc)含量均下降,妃子笑、无核荔枝TSS/TA值呈先上升后下降趋势。新球蜜荔果肉TSS和TSS/TA值最高,TA最低;而紫娘喜果肉TA含量最高,TSS/TA值最低。紫娘喜与新球蜜荔Vc含量高于其它品种。     

云南德宏羊奶果资源收集和评价简报

为开发利用羊奶果种质资源,以云南德宏的16份羊奶果种质资源为试材,主要分析果实可滴定酸、可溶性固形物和维生素C三个主要品质性状,并对所收集的羊奶果材料相关品质表现进行综合评价。结果表明：16份羊奶果可滴定酸,可溶性固形物和维生素C的变异系数分别为56%、20.72%和26.72%;根据综合评价,3号羊奶果种质资源综合表现优良。     

无核荔枝僵果病的病原菌鉴定、入侵途径及快速检测技术

2022年在海南无核荔枝上发现一种僵果病,与海南常见的荔枝病害炭疽病、酸腐病等病症差别明显,主要为害幼果,发病时幼果果实外观无明显变化,但无核荔枝完成疏果后,果实长至蚕豆大小时,发病果实的外果皮颜色变暗,剖开后内果皮发生不规则褐变,果实不再膨大,形成僵果,易造成严重的经济损失。本研究对该病害的病原菌进行分离和鉴定,对入侵途径和快速检测技术进行研究。结果表明：通过形态学鉴定、ITS、RBP2和TEF1基因序列分析,鉴定引起无核荔枝新型僵果病的病原菌为伯氏镰刀菌（Fusarium pernambucanum）。无核荔枝幼果期果实果皮受农事操作、风、刺吸性昆虫为害等损伤后,易受到病原菌的入侵发病,而果实表面无伤口时不发病。病原菌入侵主要集中在果实纵经3.2～4.8 mm的幼果期,随着果实的生长、果皮保护组织的增加和伤口的减少,病原菌难以入侵,果实发病率快速降低。基于TUB基因序列,以伯氏镰刀菌及其他分离获得的镰刀菌属菌株基因组DNA为模板进行扩增测序,根据序列信息设计筛选出一对伯氏镰刀菌的特异性引物,构建了基于普通PCR的快速高效分子检测方法,该检测方法灵敏、高效,可用于指导无核荔枝僵果病的...     

3种无核荔枝果实发育过程中内源激素含量变化动态

采用高效液相色谱法(HPLC)测定3个无核荔枝品种果实发育过程中生长素(IAA)、赤霉素(GA3)、玉米素(ZT)和脱落酸(ABA)等内源激素含量的变化,通过与有核荔枝对比分析,阐明无核荔枝果实发育过程中内源激素的变化规律,并进一步探讨荔枝无核但能发育成大果的原因。结果表明:在果实发育过程中,有核荔枝和无核荔枝果实中GA3和ABA的变化规律基本一致,IAA和ZT表现差异较大,初步认为无核荔枝和有核荔枝果实发育可能有两种不同的激素调控模式,或者果实发育与GA3和ABA关系更为密切;无核荔枝果实中高含量的IAA和低含量的ZT可能是其产生无核的一个重要原因。     

基于SRAP分子标记的特早熟荔枝种质资源遗传多样性分析

以22份特早熟、6份早熟及2份中熟荔枝种质资源为材料,利用SRAP分子标记进行遗传多样性分析,探索特早熟荔枝种质资源的亲缘关系。结果表明：对182对SRAP引物组合进行筛选,获得16对多态性高、条带清晰的SRAP引物组合,共计产生扩增条带182条,其中多态性条带140条,占76.9%。材料间遗传相似系数为0.47~0.99,根据UPGMA聚类分析,在遗传相似系数0.73处可将30份荔枝样本分成4类,其中第Ⅰ类20份,占66.7%,包括绝大多数特早熟荔枝资源;第Ⅱ类4份,占13.3%,包括‘妃子笑’与部分杂交早熟资源;第Ⅲ类和第Ⅳ类各3份,分别占10%。以上研究结果为特早熟荔枝种质资源发掘、评价及新品种培育提供理论参考。     

海南野生鹧鸪茶资源调查与鉴定评价

鹧鸪茶是具有海南地方和民族特色的代茶饮料植物和药用植物,已开发成为广受欢迎的特色旅游产品,但大规模的人为无序开发对野生资源造成了极大的破坏。通过对海南野生鹧鸪茶进行资源调查、收集保存和保护利用等研究,结果表明：在海南全省10个市县共13个调查地点中,仅2个地点的野生鹧鸪茶基本未受到人工影响,其余地点的野生植株长势较弱,人为破坏较严重,部分生境已受到人工开垦的影响;先后收集保存285份鹧鸪茶种质资源,并在异地建设种质资源圃安全保存;对收集保存的285份资源进行5个描述性状和6个数值性状的植物学鉴定评价,其中描述性状的多样性指数的变化范围为0.69~1.74,数值性状的多样性指数的变化范围为1.93~2.11,说明收集保存的鹧鸪茶种质具有丰富的遗传多样性。本研究可为人工培育优良鹧鸪茶无性品系提供了资源基础和评价数据。     

海南稻种种质资源系统调查与收集

根据“第三次全国农作物种质资源普查与收集行动”的要求，为了摸清海南岛稻种种质资源分布，2017—2021年，海南调查队开展了稻种种质资源的调查和收集工作。调查收集到普通水稻、香稻、黑米稻、糯稻、红米稻、山栏稻等6种稻种种质资源，共计109份。调查发现，海南稻种种质资源集中分布在白沙县、儋州、保亭、三亚市等中西部市县，相较于“第二次全国农作物种质资源普查与收集行动”的种质资源，增加了位于琼中、五指山、琼海、昌江、东方、乐东、文昌、海口市琼山区、儋州、白沙等10个市县区的29份资源。本次行动抢救性收集了一批古老地方稻种品种、濒危资源，丰富了已有记录种分布区域。本研究对海南岛稻种地方品种资源有了系统认识，为深入研究海南稻种资源打下了基础，为下一步新品种选育和应用提供参考。     

不同荔枝品种采后果皮褐变与多酚氧化酶关系的研究

以无核荔枝、妃子笑、紫娘喜3个荔枝品种为试材,研究了不同耐贮性荔枝品种果实采后果皮多酚氧化酶活性与果皮褐变之间的关系,结果表明,在相同贮藏阶段,3个荔枝品种中无核荔枝褐变指数最高,妃子笑次之,紫娘喜最低。不同处理条件下妃子笑、紫娘喜果皮PPO酶活性均呈先上升后下降的趋势,常温贮藏时无核荔枝果皮PPO活性逐渐下降,低温贮藏则先下降后上升再下降。果实贮藏前期,PPO结合酶、游离酶与总酶活性以无核荔枝最高,妃子笑次之,紫娘喜最低。新采收果实中,紫娘喜果皮PPO同工酶仅2条带,妃子笑3条,而无核荔枝有4条。不同处理对同工酶带数无影响,但低温减少了无核荔枝某些阶段果皮PPO同工酶带数。不同品种荔枝果皮褐变进程差异与果实贮藏前期果皮PPO酶活性差异及同工酶带数有关。     

我国麻类标准现状与分析

介绍了我国麻类标准的现状。通过分析,指出了存在的问题,主要表现在标准体系不完善、标准更新不及时,协调性差及贯彻执行不力等。提出了我国麻类标准应采取的对策。     

水稻病虫害绿色防控与统防统治融合技术模式示范

2017—2018年,在同安镇粮食产能区示范推广水稻病虫害绿色防控与统防统治融合技术模式,取得了显著成效。融合技术示范区比常规区减少用药2~3次,用药量减少37.6%,防治成本降低400元/hm^2;水稻产量增加12.8%,收益增加2 835元/hm^2。     

Effects of Organic and Chemical Fertilizers and Arbuscular Mycorrhizal Inoculation on Growth and Quality of Cucumber and Lettuce

Summary

Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer.     

春季氮肥和多效唑调控对小麦生育和产量的影响

为明确春季调控措施对冬小麦生长发育和籽粒产量的影响,以冬小麦品种石新828为材料进行田间试验,4个处理分别为:起身期追全部氮肥(除基肥外,下同)并叶面喷多效唑(N1);起身期追2/3氮肥并喷多效唑+拔节期追1/3氮肥(N2);起身期追1/3氮肥+拔节期追2/3氮肥(N3);拔节期追全部氮肥(N4)。生育期间测定群体和个体生育特性,成熟期调查产量性状。结果表明,N1和N2处理小麦拔节期的总茎数、叶面积指数(LAI)和干物质积累量均显著高于N4和N3处理。孕穗期N4和N3处理小麦的总茎数、LAI和干物质积累量显著高于N1和N2处理。开花到成熟期各处理的总茎数、LAI和干物质积累量差异均不显著。孕穗期前,不同处理的株高差异不显著,孕穗期后,N4处理的株高最高,且显著高于N1处理。各处理基部节间直径和中上部节间长的差异不显著,N4处理基部第一节间长度显著大于其他处理。随追氮时期前移或前期施氮量增多,不孕小穗数减少,结实小穗和穗粒数增加,N1比N4处理不孕小穗数显著减少,结实小穗和穗粒数显著增多。N1处理小麦成熟期的千粒重最高,且显著高于N4处理。N1处理的籽粒产量最高,且显著高于N3和N4处理。起身期追氮配合多效唑调控,可以获得比拔节期追氮更高的穗粒数和千粒重,从而获得更高的产量。     

海南百香果病虫害种类调查鉴定及其发生危害

百香果是海南省的新兴产业,也是我国多个省区扶贫攻坚的重要产业。病虫害是影响百香果产业的重要因素,随着海南百香果种植面积越来越大,病虫害对百香果产业的不利影响越来越凸显。由于缺乏百香果病虫害种类调查鉴定的基础性研究,许多种植户对田间发生的病虫害种类识别不足,从而影响了百香果病虫害的防控效果。为了摸清海南百香果种植区的病虫害种类,于2019—2021年对海南省儋州市、乐东县、屯昌县、文昌市、三亚市、东方市、保亭县、白沙县、海口市等百香果种植区的病虫害进行了系统调查与鉴定,并对其发生危害特点进行了研究。鉴定发现海南百香果种植区的病害有11种,分别是病毒病、茎基腐病、炭疽病、疮痂病、疫病、灰霉病、果腐病、褐斑病、烟煤病、藻斑病和缺镁。重要病害为病毒病和茎基腐病,危害程度分别为4级和3级,炭疽病和疮痂病危害也较重,危害程度均为2级,其他病害危害较轻。害虫有28种,分别是黄胸蓟马、茶黄蓟马、红带蓟马、美洲棘蓟马、普通大蓟马、咖啡木蠹蛾、美洲斑潜蝇、橘小实蝇、斜纹夜蛾、双线盗毒蛾、绿丽刺蛾、白带锯蛱蝶、烟粉虱、温室白粉虱、柑橘粉蚧、木槿曼粉蚧、藤壶蜡蚧、茶角盲蝽、樟颈曼盲蝽、稻绿蝽、中稻缘蝽、茶小绿叶蝉、丽球瓢蜡蝉、绿鳞象甲、眼斑芫菁、白条豆芫菁、甘薯梳龟甲和朱砂叶螨。重要害虫为黄胸蓟马和咖啡木蠹蛾,危害程度均为3级,茶黄蓟马和美洲斑潜蝇的危害也较重,危害程度均为2级,其他害虫危害较轻。软体动物3种,分别是灰巴蜗牛、同型巴蜗牛和一种尚未鉴定的蛞蝓。本研究明确了海南百香果种植区病虫害具体种类,新发现百香果病害1种和害虫24种,为海南百香果病虫害的精准防控提供技术支撑。     

Preparation and characterization of fibers of waste and fresh polyethylene terephtalate and mixtures of them

Textile fibers were obtained from secondary polyethylene terephtalate (PET) and its mixtures with primary PET at initial orientation of 18000–33000 %, rate of additional orientation drawing 3.5–6.5 times and temperature of thermal fixation 363–413 K. The fibers’ tensile strength was found to decrease and elongation at break to increase with the decrease of their linear density under the conditions of fibers formation. For the fibers based on polymer mixtures, the presence of oxidized fragments in the secondary PET limited the compatibility of the two polymers which resulted in deteriorated tensile properties. The linear density (4–16 dtex), tensile strength (30–50 cN/tex) and elongation at break (20–60 %) of the PET fibers obtained were close to these for the industrially produced polymer fibers. The values of the average diameter of the fibers formed and oriented under laboratory conditions allows classifying them between the fine and the coarse textile fibers which makes them suitable for the textile industry.     

白砂糖干燥与冷却机理及影响

砂糖的含水量、装包温度和仓储条件对其贮存保质具有重要影响。本文从白砂糖的含水分特性、干燥机理和生产过程环节等对白砂糖干燥与冷却的影响进行深入分析。由于结晶过程的包裹现象,砂糖含水分可分为表面和内部水分,白砂糖干燥过程只能去除前者。生产过程中煮糖、分蜜操作对内部水分含量有影响。贮存过程的内部水分的扩散是砂糖降质的根本原因,而装包温度和贮存条件是影响内部水分扩散的外在条件。     

Interactive Effects of Sodium and Potassium on the Growth and Photosynthesis of Spinach and Komatsuna

Abstract

Two cultivars of spinach and one cultivar of komatsuna were sand cultured using a nutrient solution with Na and K in various combinations. The growth (fresh weight of shoot) of spinach cv. Atlas was significantly increased when 1.4 mM KC1 of the 7 m M KO was replaced with 1.4 mM NaCl, although the growth was reduced when more KC1 was replaced with NaCl. In another spinach cv. All Right, however, NaCl substituting for 20% of KC1 showed no significant effects. In komatsuna, Na used in place of K at any ratio reduced the growth. The growth of spinach cv. Atlas was increased by applying 20 mM NaCl, irrespective of K dose (480 - 2400 mg K₂O per 1/2000 a Wagner pot). The growth of spinach cv. All Right was also increased by 20 mM NaCl when K was at a deficient level (480 - 960 mg K20 per pot), but was not when K was at: an excessive level (1920 - 2400 mg K₂O per pot). In komatsuna, 20 mM NaCl reduced the growth. In spinach, Na prevented the decrease of the photosynthetic rate and stomatal conductance caused by K deficiency.     

苯醚甲环唑和嘧菌酯在水稻中的残留消解动态及残留分析

本文建立了气质联用仪测定稻田环境中苯醚甲环唑和嘧菌酯的残留分析方法,对苯醚甲环唑和嘧菌酯在水稻、土壤和田水中的消解动态和残留规律进行了研究。苯醚甲环唑和嘧菌酯在糙米、稻壳、植株、土壤和田水中的最低检测浓度均为0.20 mg/kg,最小检出量为0.2 ng,在不同样品中的平均加标回收率为80.8%~109.5%,相对标准偏差在1.7%~19.7%之间。田间试验结果表明,苯醚甲环唑和嘧菌酯在水稻植株和田水中的残留消解动态规律均符合一级动力学反应模型,苯醚甲环唑在水稻植株和田水中的残留消解半衰期分别为6.3~11.6 d和1.4~11.6 d;嘧菌酯在水稻植株和田水中的残留消解半衰期分别为3.6~8.7 d和2.9~23.1 d。以推荐剂量600 g/hm2和1.5倍推荐剂量900 g/hm2,最多施药3次,距最后一次施药15 d时,苯醚甲环唑和嘧菌酯在糙米中的最高残留量分别为0.461 mg/kg和0.634 mg/kg,低于我国国家标准《食品中农药最大残留限量》(GB2763-2014)中规定的糙米中苯醚甲环唑最大残留限量0.5 mg/kg和欧盟、美国规定的糙米中嘧菌酯最大残留限量5.0 mg/kg。     

Effects of crop density and tillage system on grain yield and N uptake from soil and atmosphere of sole and intercropped pea and oat

Pea (Pisum sativum L.) and oat (Avena sativa L.) were grown as sole and mixed crops in various densities under two different tillage systems on a loess soil near Göttingen/Germany in a 2-year field experiment (2002/2003). In the conventional tillage system a mouldboard plough (CT) was used and in the minimum tillage system a rotary harrow (MT) was employed. The effect of crop density and tillage system on the grain dry matter and grain N yields, N₂ fixation and soil N uptake were determined to address the following questions: (i) which mixture compositions exhibit the highest grain yields compared to the sole crops, (ii) which mixture compositions also fix a high level of N₂ and leave low levels of residual inorganic soil N after harvest, and (iii) whether the intercrop advantage is influenced by the tillage system. For (i) the result in 2002 showed that the highest grain yields of both sole cropped pea and oat and intercropped pea and oat were achieved at the highest densities. In 2003, when the inorganic soil N content was higher and weather conditions were warmer and drier, grain yields were significantly higher than in 2002, but sole as well as intercropped pea and oat gave their highest grain yields at lower densities. For both years and tillage systems, the highest intercrop advantages were achieved in mixtures with densities above the optimal sole crop densities. The result for (ii) was that a distinctly higher proportion of nitrogen was derived from the atmosphere (Ndfa) by intercropped pea than by sole cropped pea. However, the uptake of soil N by intercropped pea and oat was not reduced in comparison with that of sole cropped oat as the decrease in the uptake of N from the soil by oat at lower oat densities in the mixture was compensated for by the soil N uptake of pea. Additionally, the N_min-N content of the soil following the mixtures and sole cropped oat did not differ, especially in the deeper soil layers because oat in mixture was forced to take up more soil N from deeper layers. Therefore, the risk of soil N losses through leaching after mixtures was lower compared to sole cropped pea. The tillage system (iii) had no significant influence on grain yield and soil N uptake, but N₂ fixation and the competitive ability of intercropped pea were higher under CT than with MT. An additional result was that intercropping led to a significantly increased grain N content of both pea and oat compared to the sole crops. The increase in grain N content from sole to intercrop was from 3.30 to 3.42% for pea and from 1.73 to 1.96% for oat as a mean for both years and tillage systems. The present study confirms that growing pea and oat as intercrops highlights potential economic and environmental benefits which still need to be understood in more detail in order to exploit intercropping to a greater extent.