八个贵州地方桃品种果实甜酸风味品质分析

为了评价贵州地方桃品种果实的甜酸风味品质,以主栽桃品种‘燕红’作对照,采用高效液相色谱法测定了贵州8个地方桃品种的果肉糖酸组分及含量。结果表明:(1)8个地方桃品种果肉中糖主要由蔗糖、葡萄糖、果糖和山梨醇组成,其中蔗糖的平均含量最高(55.62 mg/g),约占总糖的71.30%,但变异系数仅为17.92%;8个地方桃品种中,‘米桃’的葡萄糖与果糖含量差异较大,其果糖/葡萄糖的比值为1.21,而其它7个品种的葡萄糖与果糖含量相近。(2)8个地方桃品种果肉中有机酸主要由苹果酸、柠檬酸、奎宁酸和莽草酸组成,其中苹果酸含量最高,约占总酸的60.61%,但在‘白花桃’果实中有机酸含量以奎宁酸为主。(3)对8个地方桃品种果实的糖酸组分进行主成分分析发现,苹果酸含量和山梨醇含量的载荷系数分别为0.910和0.897,说明它们是影响果实甜酸风味的主导因素,且对改善果实的甜酸风味品质具有重要作用。8个贵州地方桃果实的甜酸风味分别为:‘黄腊桃’为甜,‘血桃’、‘青桃’、‘镇远桃’、‘红枫桃’为酸甜,‘白花桃’、‘西桃’和‘米桃’为酸。     

海水胁迫对菠菜叶绿素代谢的影响

以耐海水品种‘荷兰3号’和海水敏感品种‘圆叶菠菜’为试验材料,采用营养液栽培,研究海水胁迫对菠菜叶绿素代谢的影响。结果表明,海水胁迫下,2个菠菜品种叶片的叶绿素a(Chl a)、叶绿素b(Chl b)和总叶绿素含量以及叶绿素合成前体———原叶绿素酸(Pchl)、镁原卟啉IX(Mg-proto IX)、原卟啉IX(Proto IX)和尿卟啉原III(UroIII)含量均明显降低,而胆色素原(PBG)和δ-氨基酮戊酸(ALA)积累,‘圆叶菠菜’的变化幅度大于‘荷兰3号’。海水胁迫下,‘荷兰3号’叶片的叶绿素酶(Chlase)活性无显著变化,胆色素原脱氨酶(PBGD)和尿卟啉原III合酶(UROS)活性在胁迫第3天显著下降,而‘圆叶菠菜’Chlase活性显著上升,PBGD和UROS活性显著下降。研究发现,在海水胁迫条件下,菠菜叶片的叶绿素合成代谢受阻,受阻位点位于PBG→UroIII的转化过程,其中‘圆叶菠菜’的受阻程度大于‘荷兰3号’;耐海水品种‘荷兰3号’叶片叶绿素含量降低主要由叶绿素合成代谢受阻引起,而海水敏感品种‘圆叶菠菜’叶绿素含量的降低则是由叶绿素合成受阻和叶绿素降解共同作用的结果。     

5个番石榴品种果实食用品质和香气特征分析

为比较番石榴(Psidium guajava)不同品种果实的外观、营养价值和香气特征,采用国家标准方法,对5个番石榴品种(‘红宝石’、‘粉红蜜’、‘西瓜’、‘水蜜’、本地种)果实的外观和营养成分进行测定,采用顶空气质联用(HS-GC-MS)技术对5个品种果实的香气成分进行测定。结果表明,不同品种果实外观及营养成分差异明显。‘水蜜’的果形指数最低,果实扁圆形,种籽最少;大多数糖类物质(总糖、还原糖、蔗糖等)、糖酸比、总酚含量最高;果糖、VC和总黄酮含量位居第2;总酸、脂肪、粗纤维、灰分含量最低。主成分分析表明,‘水蜜’作为鲜食水果的食用品质最高。己醛和石竹烯是红肉型品种的特征风味物质,3-羟基-2-丁酮是白肉型品种的特征香气成分。     

不同生育期花生叶片蛋白质含量及氮代谢相关酶活性分析

以5个珍珠豆型花生(Arachis hypogaea Linn.)品种(系)‘汕E’(‘Shan E’)、‘汕G’(‘Shan G’)、‘TH’、‘TJ’和‘泉花7号’(‘Quanhua No.7’)为研究对象,分析了花针期、结荚期和饱果期花生叶片中可溶性蛋白质含量及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH)活性的变化趋势,并比较了5个品种(系)荚果和秆产量的差异。结果表明:在3个生育期内,5个花生品种(系)叶片可溶性蛋白质含量和GDH活性的变化趋势基本一致,而NR和GS活性的变化趋势则有差异。其中,可溶性蛋白质含量均呈"低—高—低"的变化趋势,在结荚期最高;GDH活性均逐渐升高,至饱果期达最高;‘泉花7号’叶片NR活性呈"高—低—高"的变化趋势,而其他4个品种(系)叶片NR活性均逐渐降低;‘汕E’、‘TJ’和‘泉花7号’叶片GS活性呈逐渐降低趋势,而‘汕G’和‘TH’叶片GS活性呈"低—高—低"的变化趋势。总体上看,5个品种(系)中,‘汕G’和‘泉花7号’叶片的可溶性蛋白质含量及NR和GDH活性、‘汕E’叶片的NR和GS活性以及‘TH’叶片的GDH活性均较高。5个品种(系)的2个产量指标(单株荚果鲜质量和单株秆鲜质量)均有明显差异,总体上看,‘汕G’、‘泉花7号’和‘TH’的2个产量指标均较高,而‘汕E’和‘TJ’的2个产量指标均较低。综合分析结果显示:‘汕G’和‘泉花7号’叶片可溶性蛋白质含量及NR和GDH活性均相对较高,其荚果和秆产量也均较高,表明花生荚果和秆产量与不同生育期叶片氮代谢水平有一定关系。     

不同海拔地区烤烟叶片光合特性的日变化特征

以3个遗传背景不同的烤烟品种(‘K326’、‘云烟87’、‘中烟103')为材料,研究不同海拔(500、900、1 300m)地区烤烟叶片的光合气体交换与叶绿素荧光参数的日变化特征,为烟草种植区划分和区域适宜烤烟品种配置提供理论依据.结果显示:(1)各品种烤烟叶片的净光合速率(Pn)、气孔导度(Gs)和水分利用率(WUE)的日均值与海拔呈正相关关系,而其胞间CO2浓度(Ci)和蒸腾速率(Tr)的日均值与海拔高度呈负相关关系.(2)各品种叶片Pn、Ci、Gs及Tr的日变化在高海拔(1 300 m)地区呈“单峰”曲线变化,没有明显的光合“午休”现象;而在较低海拔(500 m和900m)地区呈不对称“双峰”曲线变化,在晴天中午时段叶片光合受到明显抑制.(3)3个烤烟品种叶片的PSⅡ原初光能转换效率(Fv/Fm)和PSⅡ潜在活性(Fv/F0)随着海拔的升高而提高.(4)各品种的日光合总量(∑Pn)均呈现随海拔升高而增加的趋势,且‘云烟87'的日光合总量显著高于其他两个品种;各品种的日蒸腾总量(∑Tr)均以海拔900m最高,海拔1 300 m最低.研究表明,海拔因素是影响和制约烤烟叶片光合特性及光合生产能力的关键因素,在品种布局时必须考虑其在不同海拔地区的光合特性.     

细胞分裂素种类及添加量对蓝浆果叶片离体再生的影响

以南方高丛蓝浆果(Vaccinium corymbosum hybrids)品种‘南月’(‘Southmoon’)优选系A18和兔眼蓝浆果(V.ashei Reade)品种‘灿烂’(‘Brightwell’)离体叶片为外植体,研究了培养基中添加不同浓度TDZ(0.5、1.0和2.0mg·L-1)、CPPU(2.0、4.0和8.0 mg·L-1)、ZT(2.0、4.0和8.0 mg·L-1)和2iP(4.0、8.0和16.0 mg·L-1)对叶片不定芽再生的影响.结果表明:在培养基中添加TDZ和CPPU对叶片不定芽的诱导效果优于ZT和2iP,再生率有显著差异(P＜0.05).TDZ诱导不定芽出现所需的时间最短且再生率最高,不定芽密集并呈深绿色;其中,在添加0.5 ～2.0 mg·L-1TDZ的培养基上,A18叶片再生率均为100.00％,‘灿烂’叶片再生率最高达79.17％.CPPU也有较强的诱导能力但不定芽出现所需的时间推迟3～5d,且不定芽的密集程度也有所降低;其中,在添加2.0～8.0 mg·L-1CPPU的培养基上,A18叶片再生率为100.00％～93.75％;而‘灿烂’叶片再生率随CPPU质量浓度提高呈下降趋势(72.91％ ～47.91％).ZT和2iP诱导能力差,在添加不同质量浓度ZT和2iP的培养基上A18和‘灿烂’叶片再生率均为0.00％.此外,A18和‘灿烂’的再生能力有差异,在相同条件下A18叶片的再生能力优于‘灿烂’叶片.研究结果显示:基因型以及培养基中细胞分裂素的种类和添加量是影响不同品种蓝浆果叶片不定芽再生的主要因素.     

不同氮浓度对兔眼蓝浆果不同品种幼苗生长和光合生理的影响

为确定兔眼蓝浆果( Vaccinium ashei Reade)不同品种苗期的适宜施氮量,以兔眼蓝浆果早熟品种‘阿拉帕哈’(‘Alapha’)、中熟品种‘园蓝’(‘Gardenblue’)和晚熟品种‘芭尔德温’(‘Baldwin’)的组培苗为实验材料,采用水培法研究了不同氮浓度(0、1、2和4 mmol·L-1)对幼苗生长、根和叶中全氮含量、叶片光合生理特性的影响。结果表明：与对照(0 mmol·L-1氮)相比,经1、2和4 mmol·L-1氮处理后3个兔眼蓝浆果品种的单株茎叶干质量显著增加,根冠比显著降低;但品种‘园蓝’的单株根干质量显著高于对照,另2个品种的单株根干质量与对照无显著差异。随着营养液中氮浓度的提高,3个兔眼蓝浆果品种根的全氮含量及品种‘阿拉帕哈’叶的全氮含量均逐渐增加,且在4 mmol·L-1氮处理下最高;品种‘园蓝’和‘芭尔德温’叶的全氮含量呈先升高后降低的趋势,且均在2 mmol·L-1氮处理下最高;各处理组根和叶的全氮含量均显著高于对照。经1、2和4 mmol·L-1氮处理后,3个兔眼蓝浆果品种叶片的叶绿素a、叶绿素b和总叶绿素含量以及PSⅡ最大光化学效率( Fv/Fm )均呈先升高后降低的趋势,且均显著高于对照。各处理组中,品种‘园蓝’叶片的净光合速率( Pn)、气孔导度( Gs)、胞间CO2浓度( Ci)和蒸腾速率( Tr)均显著高于对照;品种‘芭尔德温’叶片的Pn值在4 mmol·L-1氮处理下显著低于对照,Gs和Tr值在2 mmol·L-1氮处理下显著高于对照,Ci值与对照无显著差异;与对照相比,品种‘阿拉帕哈’叶片的Pn值在1和4 mmol·L-1氮处理下显著提高,Gs值在1 mmol·L-1氮处理下显著提高,Tr值在1和2 mmol·L-1氮处理下显著提高,而Ci值则在4 mmol·L-1氮处理下显著降低。综合分析结果显示：适度增施氮肥可提高兔眼蓝浆果不同品种幼苗的茎叶生长、改善其光合性能,但对根系生长无明显的促进作用。在营养生长期兔眼蓝浆果不同品种的需氮量存在差异,其中品种‘园蓝’更适宜高氮环境,而施用少量氮肥即可促进品种‘芭尔德温’和‘阿拉帕哈’幼苗地上部分生长。     

不同产地‘金圆’猕猴桃低温贮藏下的生理指标及贮藏性变化

以中华猕猴桃(Actinidia chinensis Planch.)黄肉新品种‘金圆’果实为材料,通过低温贮藏实验(1℃±0.5℃,相对湿度90%~95%),系统研究武汉和六盘水所产‘金圆’果实的生理指标及贮藏性。结果显示,两地‘金圆’果实硬度和色彩角(h值)随贮藏时间延长而逐渐下降,硬度在前20 d下降幅度大。果实可溶性固形物(SSC)含量和干物质在贮藏期间变化规律基本一致,六盘水产果实的SSC和干物质含量高于武汉。武汉产果实VC、可溶性总糖、可滴定酸含量仅在80 d时高于六盘水,其他时间均低于六盘水。两地果实的固酸比和糖酸比变化一致,六盘水产果实固酸比(SSC/TA)和糖酸比(SS/TA)在80 d时均达到峰值,而武汉产果实只有糖酸比达到峰值。随贮藏时间延长,两地果实的失重率均缓慢上升,160 d时武汉和六盘水果实的失重率分别为2.82%和2.55%;在贮藏前60 d两地果实腐烂率较低,之后上升较快,160 d时六盘水产果实腐烂率是武汉的1.77倍。本研究结果表明六盘水产‘金圆’果实的风味品质优于武汉,而武汉产果实贮藏性更好些。     

不同梨品种果实有机酸含量变化与相关酶活性的研究

以梨品种‘鸭梨’、‘茌梨’和‘八里香’为试材,对不同品种果实有机酸积累及相关酶活性随发育的动态变化特征进行分析比较,探讨果实有机酸含量与相关酶活性的关系。结果表明:(1)梨果实发育过程中有机酸含量呈逐渐下降趋势,果实成熟时的总有机酸含量以‘茌梨’最高,‘鸭梨’次之,‘八里香’最低,且3品种间总酸含量差异显著。(2)果实发育后期,‘鸭梨’、‘茌梨’和‘八里香’的柠檬酸含量几乎相同,而苹果酸的含量差异显著,说明苹果酸是引起品种间总酸含量差异的主要因素。(3)在苹果酸代谢中,不同品种间NADP-ME酶活性在果实发育后期差异显著,而NAD-MDH和PEPC酶活性无显著差异,表明NADP-ME酶是引起‘鸭梨’、‘茌梨’和‘八里香’成熟果实苹果酸含量差异的主要原因。(4)不同品种的柠檬酸代谢酶CS、Cyt-ACO、Mit-ACO和NAD-IDH的活性变化趋势一致,且成熟时无显著差异,表明它们不是引起梨果实酸含量差异的主要原因。(5)梨果实发育过程中有机酸含量与相关代谢酶活性的相关性分析表明,苹果酸和柠檬酸代谢酶共同影响梨果实的酸含量水平。     

不同反光膜对设施葡萄光合特性和叶片糖代谢的影响

以‘京秀’葡萄为试材,研究了蓝膜、红膜、铝膜3种反光膜对设施葡萄光合特性和叶片糖代谢的影响。结果显示:红膜和蓝膜处理的葡萄叶片的净光合速率均显著高于对照(不铺设反光膜);在果实发育前期,各处理的叶绿素含量和叶绿素b/a值均大于对照,而后期均低于对照;蓝膜和红膜处理叶片的蔗糖含量较高,而蓝膜处理叶片中的蔗糖合酶(SS)和蔗糖磷酸合酶(SPS)活性最高;各铺膜处理均比对照提高了葡萄果实鲜量和可溶性糖含量、降低可滴定酸含量,且蓝膜处理显著优于红膜和铝膜。研究表明,在设施栽培条件下,地面铺设蓝色反光膜可显著提高葡萄叶片的光合速率和叶片中碳水化合物的关键合成酶活性,并显著提高葡萄果实品质。     

蓝浆果花冠形态特征及其与果实横径相关性的分析

对兔眼蓝浆果（Vaccinium ashei Reade）、北方高丛蓝浆果（V.corymbosum L．）和南方高丛蓝浆果（V.corymbosum hybrids）3个品种群及南方高丛蓝浆果实生系的花冠长度、花冠宽度、花冠长宽比和花冠口径大小等特征进行了测定和比较,并研究了花冠形态特征参数与果实横径的相关性。研究结果表明,蓝浆果不同品种群间和同一品种群内不同品种间的花冠形态特征参数差异较大;依据花冠形态特征参数,可将供试的兔眼蓝浆果和南方高丛蓝浆果各品种及南方高丛蓝浆果各实生系初步划分为4种类型,将供试的北方高丛蓝浆果各品种划分为3种类型。此外,只有南方高丛蓝浆果各品种及其实生系的果实横径与花冠宽度相关性显著（P〈0．05）,相关系数分别为0．639和0．324。     

兔眼蓝浆果品种果实养分测定

对南京地区引自美国的１２个兔眼蓝浆果品种果实主要营养成分包括可溶性固形物、糖、酸、水溶性维生素、氨基酸、矿质元素进行了测定,并与原产地进行了比较。大多数品种果实糖分含量高而酸度低,糖酸比高,风味甜而微酸。Ｂ族维生素含量明显高于苹果、柑橘和黑莓。氨基酸含量品种间差异大,Ｄｅｌｉｔｅ、Ｗｏｏｄａｒｄ、Ｃｅｎｔｕｒｉｏｎ和Ｇａｒｄｅｎｂｌｕｅ含量最高。Ｇａｒｄｅｎｂｌｕｅ大部分矿质元素,特别是Ｃａ、Ｆｅ、Ｚｎ、Ｋ的含量较高,Ｐｒｅｍｉｅｒ和Ｗｏｏｄａｒｄ的Ｓｅ含量高,Ｃｌｉｍａｘ的Ｚｎ含量高。考虑到品种的适应性,特别是丰产性表现,认为Ｇａｒｄｅｎｂｌｕｅ和Ｔｉｆｂｌｕｅ二品种在南京地区发展前途较大。     

Bee visit rates vary with floral morphology among highbush blueberry cultivars (Vaccinium corymbosum L.)

As the human population has increased, so too has the demand for biotically pollinated crops. Bees (Apoidea) are essential for pollen transfer and fruit production in many crops, and their visit patterns can be influenced by floral morphology. Here, we considered the role of floral morphology on visit rates and behaviour of managed honey bees (Apis mellifera) and wild bumble bees (genus Bombus), for four highbush blueberry cultivars (Vaccinium corymbosum L.). We measured five floral traits for each cultivar, finding significant variation among cultivars. Corolla throat diameter may be the main morphological determinant of visit rates of honey bees, which is significantly higher on the wider flowers of cv. ‘Duke’ than on ‘Bluecrop’ or ‘Draper’. Honey bees also visited cv. ‘Duke’ legitimately but were frequent nectar robbers on the long, narrow flowers of cv. ‘Bluecrop’. Bumble bees were infrequent (and absent on cv. ‘Draper’) but all observed visits were legitimate. Crop yield was highest for the cultivar with the highest combined (honey bee + bumble bee) visit rate, suggesting that aspects of floral morphology that affect pollinator visit patterns should be considered in crop breeding initiatives.     

Pollination efficiencies of three bee (Hymenoptera: Apoidea) species visiting rabbiteye blueberry

Inadequate bee pollination limits rabbiteye blueberry, Vaccinium ashei Reade, production in the some areas of the southeastern United States. Honey bees, Apis mellifera L., are currently the only manageable pollinators available for pollinating V. ashei. However, a new adaptable pollinator for rabbiteye blueberry, Osmia ribifloris Cockerell, was successfully reared and flown in captivity. The bee nested successfully in wooden shelters and conferred superior fruit set to 2-yr-old potted, rabbiteye blueberry bushes. Pollination efficiency or the percentage of blueberry flowers to set fruit after being visited once by a female O. ribifloris was comparable to that of the female blueberry bee Habropoda laboriosa (F.) and worker honey bees. Interestingly, honey bees once thought to be inefficient pollinators of rabbiteye blueberry were found to be very efficient, especially for 'Climax' and 'Premier' flowers.     

Nectar robbery by bees Xylocopa virginica and Apis mellifera contributes to the pollination of rabbiteye blueberry

Honey bees, Apis mellifera L., probe for nectar from robbery slits previously made by male carpenter bees, Xylocopa virginica (L.), at the flowers of rabbiteye blueberry, Vaccinium ashei Reade. This relationship between primary nectar robbers (carpenter bees) and secondary nectar thieves (honey bees) is poorly understood but seemingly unfavorable for V. ashei pollination. We designed two studies to measure the impact of nectar robbers on V. ashei pollination. First, counting the amount of pollen on stigmas (stigmatic pollen loading) showed that nectar robbers delivered fewer blueberry tetrads per stigma after single floral visits than did our benchmark pollinator, the southeastern blueberry bee, Habropoda laboriosa (F.), a recognized effective pollinator of blueberries. Increasing numbers of floral visits by carpenter bee and honey bee robbers yielded larger stigmatic loads. As few as three robbery visits were equivalent to one legitimate visit by a pollen-collecting H. laboriosa female. More than three robbery visits per flower slightly depressed stigmatic pollen loads. In our second study, a survey of 10 commercial blueberry farms demonstrated that corolla slitting by carpenter bees (i.e., robbery) has no appreciable affect on overall V. ashei fruit set. Our observations demonstrate male carpenter bees are benign or even potentially beneficial floral visitors of V ashei. Their robbery of blueberry flowers in the southeast may attract more honey bee pollinators to the crop.     

南方高丛蓝浆果‘南月’实生后代果实特性的变异分析

对南方高丛蓝浆果（Vaccinium corymbosum hybrids）品种‘南月’（‘Southmoon’）实生后代的单果质量、果实横径、可溶性固形物含量、单果种子数、果色、口感以及蒂痕类型等果实特征的变异进行了分析。结果表明,‘南月’实生后代的单果质量为0．64～2．15g,果实横径为10．0～16．4mm;果实可溶性固形物含量为9．1％-15．8％,其中有37％的单株果实可溶性固形物含量在12．0％以上;单果种子数为3～93粒,有18％的单株单果种子数小于25粒;果实颜色以蓝紫色和黑蓝紫色为主,比例分别为50％和42％;果实口感以中等和好2个等级为主,比例分别为50％和40％。在对果实的主要特征和经济性状进行评估的基础上,初步筛选出21个‘南月’实生后代优良单株。     

Susceptibility of low-chill blueberry cultivars to Mediterranean fruit fly, oriental fruit fly, and melon fly (Diptera: Tephritidae)

No-choice tests were conducted to determine whether fruit of southern highbush blueberry, Vaccinium corymbosum L., hybrids are hosts for three invasive tephritid fruit flies in Hawaii. Fruit of various blueberry cultivars was exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal development and adult emergence. Each of the 15 blueberry cultivars tested were infested by oriental fruit fly and Mediterranean fruit fly, confirming that these fruit flies will oviposit on blueberry fruit and that blueberry is a suitable host for fly development. However, there was significant cultivar variation in susceptibility to fruit fly infestation. For oriental fruit fly, 'Sapphire' fruit produced an average of 1.42 puparia per g, twice as high as that of the next most susceptible cultivar 'Emerald' (0.70 puparia per g). 'Legacy', 'Biloxi', and 'Spring High' were least susceptible to infestation, producing only 0.20-0.25 oriental fruit fly puparia per g of fruit. For Mediterranean fruit fly, 'Blue Crisp' produced 0.50 puparia per g of fruit, whereas 'Sharpblue' produced only 0.03 puparia per g of fruit. Blueberry was a marginal host for melon fly. This information will aid in development of pest management recommendations for blueberry cultivars as planting of low-chill cultivars expands to areas with subtropical and tropical fruit flies. Planting of fruit fly resistant cultivars may result in lower infestation levels and less crop loss.     

Lethal and sublethal activities of imidacloprid contribute to control of adult Japanese beetle in blueberries

Field-based bioassays and residue profile analysis were used to determine the relative importance of lethal and sublethal effects of imidacloprid on adult Japanese beetle, Popillia japonica Newman, in blueberries, Vaccinium corymbosum L. Field-based bioassays assessed adult mortality and knockdown, and fruit and leaf injury from Japanese beetles exposed to 4-h and 7-d field-aged residues of imidacloprid, and the conventional insecticides azinphosmethyl and esfenvalerate. Azinphosmethyl and imidacloprid caused high levels of mortality when beetles were exposed to blueberry shoots with ripe fruit 4 h postapplication, and all compounds protected blueberry fruit and foliage from beetle feeding. Azinphosmethyl and esfenvalerate caused significant Japanese beetle mortality when adults were exposed to blueberry shoots 7 d postapplication, whereas imidacloprid residues caused effects that protected leaves, although not of ripe fruit. When beetles were exposed to shoots with immature green fruit, relatively more leaf feeding and mortality were observed, suggesting that earlier treatment timings may be most effective for systemic neonicotinoids. Japanese beetle mortality was highly correlated with imidacloprid fruit and leaf surface residues, whereas sublethal feeding deterrent effects were observed after the surface residues diminished. The value of the plant-insect-chemistry model for describing the spatial and temporal dimensions of insecticide modes of activity is discussed in terms of optimizing crop protection.     

‘灿烂’蓝莓组培与快繁技术

以蓝莓良种‘灿烂’半木质化茎段为材料,通过对增殖培养基以及生根培养基的筛选,建立蓝莓高效组培快繁技术体系。结果表明,最佳的增殖培养基为1/2MS＋2.0 mg·L^-1 ZT＋0.01 mg·L^-1 NAA＋30 g·L^-1白糖＋6.5 g·L^-1琼脂,芽诱导率为87%,增殖系数达3.6;ZT 1.0～2.0 mg·L^-1对不定芽诱导效果明显,随着ZT浓度的提高,愈伤组织产生越明显,影响增殖苗的质量。最佳生根培养基为1/2MS＋1.5 mg·L^-1 IBA＋0.01 mg·L^-1 NAA ＋25 g·L^-1白糖＋7.0 g·L^-1琼脂,pH值5.8,生根率70%,IBA浓度从0.5 mg·L^-1提高到1.5 mg·L^-1,生根越多,根系越壮,但也产生更多愈伤组织影响生根质量。炼苗10 d后移栽至草炭土,成活率78%。