不同日期采摘的不同品种澳洲坚果的氨基酸分析

为深入了解不同时间采收的不同品种澳洲坚果果仁中氨基酸的含量差异性,从而为其有针对性和选择性的采收和加工提供参考依据,对广西壮族自治区内3个主栽品种(桂热1号、OC、695)澳洲坚果果仁中氨基酸的含量与组成进行了测定与分析,比较分析了不同品种间氨基酸的差异性、必需氨基酸和氨基酸总含量的变化情况,并采用模糊识别法和氨基酸比值系数法对其营养价值进行了评价。结果表明:澳洲坚果果仁中含有7种人体必需氨基酸,其中蛋氨酸的含量差异性较大,其必需氨基酸含量和氨基酸总量呈显著正相关关系,限制性必需氨基酸的种类随采摘时间的改变而有所改变,其果仁蛋白与FAO/WHO推荐模式值和全蛋白模式值的贴近度均较高。澳洲坚果果仁中氨基酸的组成合理,各种氨基酸的比例均衡且有较高的营养价值;广西壮族自治区内3个主栽品种中的695品种,虽为搭配品种,但其氨基酸营养价值最高。     

广州地区澳洲坚果抽梢与坐果的关系

广州地区澳洲坚果一年主要抽生三次梢,以多年生枝和春梢为主要结果母枝,分别占43.1%和39.1%.结果能力以更梢母枝最强,平均每枝坐果3.0个,其次为多年生枝(2.0个).平均花坐果率0.22%.坐果数与结果母枝长度、粗度、粗/长比和叶片数无显著相关,与花序数和初始坐果数密切相关(R~2=0.7653).树冠郁闭条件极显著地减少初始坐果数.花后5周内落掉总花量的99%以上.幼果的另一个脱落高峰在花后第5至8周,主要是旺盛营养生长与迅速生长的果实的营养竞争所致.     

广东沿海地区澳洲坚果风害调查研究

经16年中11次风害调查：澳洲坚果抗风性差,属忌热带风暴作物;10年生前,各品种抗风性强弱依次为;OwnChoice、Kau（344）、Ikaika（333）、Keauhou（246）、Makai（800）。在平均风力低于9级、阵风低于10级、无强热带风暴出现的地区,可选择避风地域配置防护林种植;在平均风力高于9级、阵风达11级、有台风出现的地区,不宜大面积种植。     

均匀设计优化澳洲坚果SRAP反应体系

以澳洲坚果部分种质为试材,采用U25(55)均匀设计表,对SRAP-PCR反应体系中Taq DNA聚合酶、模板DNA、dNTPs、Mg2+、引物5个组分的浓度进行优化。结果表明澳洲坚果25μL的SRAP反应体系的最佳组分包括2.5μL10×PCR buffer、1 UTaq DNA聚合酶、40 ng模板DNA、0.2 mmol/LdNTPs、0.2μmol/L引物和3.0 mmol/LMg2+。利用所确立的体系对部分澳洲坚果种质进行扩增的结果清晰可靠,多态性好。     

世界澳洲坚果业之现状与前景

在１１０年的发展过程中,澳洲坚果在一些国家和地区形成了产业,许多国家正在引种试种。主产国已培育出一些优良品种。全球种植面积已达４万多ｈｍ２,年产鲜果６万多ｔ,果仁销售量１万多ｔ。由于适应范围较广、经济效益较高,发展前景良好。     

Postharvest dropping of macadamia nut-in-shell causes damage to kernel

Macadamia nuts (‘nuts-in-shell’) are subjected to many impacts from dropping during postharvest handling. Kernels are enclosed in hard shells and quality may be lost from damage incurred during postharvest dropping. Kernel quality loss from dropping macadamias was investigated in three experiments in which nuts of several cultivars at different moisture contents were dropped onto a bed of nuts-in-shell or a metal plate. For each dropped treatment there was an undropped control at the same moisture content. Dropped and control kernels were assessed for quality parameters: whole kernel; shoulder damage; weight of pieces; oily kernels; and dusty kernels. Dropped and control kernels were also examined by scanning electron microscopy (SEM). Dropping macadamia nuts-in-shell at 3% moisture content onto nuts-in-shell significantly increased shoulder damage, oily kernels and dusty kernels. Shoulder damage doubled compared with the control (30% cf. 15%). Oily kernels more than doubled (38% cf. 18%). There were very few dusty kernels in controls at 3% moisture content, but 15–30% of kernels were dusty when dropped. Kernel quality was also reduced at higher moisture content when nuts were dropped onto nuts-in-shell twice, once at 10% and once at 20% moisture content. Shoulder damage was almost three times the control (46% cf. 16%), and 10% of kernels were dusty while controls had no dusty kernels. SEM showed that dropping caused an abraded abaxial cuticle with visible dust particles. Oily appearance following dropping was an indicator of cell membrane damage and potential for further deterioration in quality. Typical macadamia postharvest practices such as frequent dropping cause significant commercial losses due to quality reduction, visible as shoulder damage, oiliness and dustiness.     

澳洲坚果幼苗对水分胁迫的生理响应

采用田间防雨旱棚方法研究了8个澳洲坚果品种(Hy、A16、863、951、695、特、D4和Daddow)幼苗对水分胁迫的生理响应。结果表明,所有测定指标在3次测定时间、4个水分处理和8个品种间差异均极显著。在水分胁迫(CK、L)处理下,澳洲坚果幼苗叶片中渗透调节物质可溶性糖含量、脯氨酸含量增加;活性氧清除系统中的SOD和POD活性先升高后下降,但变化规律又有所不同;叶绿素含量降低。在水分饱和(N、M)处理下,澳洲坚果叶片的各项指标的变化趋势与水分胁迫处理下截然相反。对8个品种综合分析表明,耐旱能力从强到弱依次为951>695>Daddow>Hy>A16>863>D4>特。     

Products from paradise: The social construction of Hawaii crops

Global competition has made thetraditional sugarcane and pineapple industriesincreasingly non-viable in Hawaii. One initiative torevive the agricultural sector calls for diversifyinginto non-traditional export crops that gains highervalue by attaching the paradise identity such as freshpineapples, macadamia nuts, or tropical flowers.Drawing from cases of pineapples and macadamia nuts,this paper examines how Hawaii's foodstuffs were ableto capture a premium value of place-association due tothe social construction of Hawaii as a place. Anexpansion of the niche markets, however, has allowedthe symbolic meaning of these products to beappropriated and reconstituted by global interests.Without confronting the fundamental problemsassociated with land and labor relations in Hawaii,Hawaii producers are caught in a niche-markettreadmill. They continuously seek new potentials forhigh-value crops, but are unable to maintain controlbeyond their inventive stage.     

贵州4个澳洲坚果品种不同树龄期的产量表现

为了解澳洲坚果在贵州的产量表现,以引进的4个澳洲坚果品种为试材,研究初产期不同树龄与产量的表现。结果表明：随着树龄的增长,4个品种的总产量呈快速增长,三年累计总产量表现为O.C＞H2＞HAES 788＞HAES 344,O.C在不同树龄阶段总产量均高于其他品种;平均单株产量品种O.C显著高于其它3个品种,H2在第9年单株产量出现较大增长,HAES 344始终最低;O.C的总产量和平均单株产量的增长率均为最低,H2平均单株产量的增长率最高,且在第9年总产量和平均单株产量的增长量均最高;4个品种单株产量的平均变异度O.C的最小,其次为HAES 788、H2和HAES 344;随树龄增长,O.C低增长（小于50%）的单株比例增加,H2高增长（大于等于200%）的单株比例增加;HAES 788中增长（大于等于50%小于200%）的比例增多,HAES 344低增长的比例增多。在贵州望谟生态条件下,品种O.C在不同树龄阶段总产量、单株产量、稳定性表现均优于其它三个品种。     

澳洲坚果不同品种间叶绿素荧光特性的研究*

研究不同澳洲坚果品种叶绿素含量及叶绿素荧光特性,以期为选育优良品种及高效栽培提供科学依据。结果表明：不同澳洲坚果品种间叶绿素a含量、叶绿素b含量、PSII潜在活性（Fv/Fo）、PSII的原初光能转换效率（Fv/Fm）、光合电子传递效率（ETR）和光化学猝灭系数（qP）均存在极显著差异;各品种间实际光化学量子产额（ΦPSII）差异显著;叶绿素a/b值和非光化学猝灭系数（qN）差异不显著。相关性分析结果表明：叶绿素a含量与叶绿素b含量、Fv/Fo与Fv/Fm、ETR与Fv/Fo、Fv/Fm和ΦPSII之间均呈极显著正相关,ΦPSII与qN呈极显著负相关,ETR与qN呈显著负相关。十个品种聚类后可分成三个类群。‘O.C’和‘A16’具有较好的光合性能。‘NG8(X8)’光合效率最低。