三亚地区设施苦瓜蜜蜂授粉效果研究初报

采用蜜蜂为设施栽培苦瓜授粉,以人工授粉为对照.试验结果表明:蜜蜂授粉座果率低于人工授粉;蜜蜂授粉能显著提高果实的VC含量;能提高果实的长度、横径和果肉厚,显著提高单瓜重,但单株产量差异不显著.通过改进苦瓜设施栽培管理措施,蜜蜂授粉技术可作为苦瓜设施栽培的综合配套技术加以推广应用.     

断根嫁接对冬瓜产量和品质的影响

为了研究断根嫁接对冬瓜产量和品质的影响,本研究利用‘川砧1号’南瓜砧木和彭州’青粉冬瓜’进行断根嫁接.结果表明,利用“川砧1号”南瓜作为嫁接砧木,断根嫁接后,增加了冬瓜叶片长和宽,增大了叶片叶面积,能显著增加植株茎粗和冬瓜产量,平均单瓜增产达24.25％.断根嫁接后冬瓜果肉的糖酸比提高,维生素C和硝酸盐含量降低,可溶性固形物、氨基酸、蛋白质和粗纤维含量变化不显著.因此,以“川砧1号”南瓜为砧木的断根嫁接,既能够防治冬瓜枯萎病等土传病害,增加产量,而且不会使冬瓜品质变差,可以在各冬瓜产区大力推广.     

苦瓜枯萎病抗性鉴定与抗性遗传规律研究

 以4 份田间抗性水平不同的苦瓜为材料,探讨了适用于苦瓜苗期人工接种枯萎病菌的抗性 鉴定方法;以此为基础,对来自国内外的43 份苦瓜种质资源进行了抗源筛选,以其中的抗病亲本‘0417’ 和感病亲本‘472113’为材料,研究了苦瓜对枯萎病抗性的遗传规律。结果表明,直接水培接种法是较适 合于苦瓜苗期枯萎病抗性鉴定的方法,适宜的接种菌液孢子浓度为4 × 106 · mL-1。在苦瓜种质资源中,枯 萎病抗源普遍存在,尤以野生种或半栽培种抗病性较强。苦瓜枯萎病抗性受单一显性核基因控制,其广 义遗传力为90.78%。     

加乐多土壤调理剂在瓜类蔬菜连作地上的应用效果

为改善瓜类蔬菜种植地连作障碍,探讨了土壤调理剂加乐多的应用效果。试验结果表明,与未施加乐多的处理相比,施用加乐多后,瓠子植株长势旺盛,分枝多,产量增加233．8kg／667m2,增产12％,增收1636．6元／667m2;且提高了土壤pH值,增强了瓠子的耐涝性和抗霜霉病和灰霉病的能力。     

瓠瓜KNOX基因家族全基因组鉴定及组织表达分析

【目的】 探明瓠瓜KNOX基因家族特征,在瓠瓜全基因组水平上对KNOX基因家族成员进行鉴定和分析,研究其组织表达模式。【方法】利用生物信息学方法,对瓠瓜KNOX家族基因成员进行鉴定、编码蛋白理化性质分析及家族成员结构域和保守基序分析,利用MEGA 5.05软件构建系统进化树,采用实时荧光定量PCR技术,分析KNOX基因在瓠瓜不同组织（根、茎、叶、花、果实）中的表达情况。【结果】鉴定到12个瓠瓜KNOX家族基因,这些基因分布在6条染色体上,且均定位于细胞核。大多数瓠瓜KNOX家族蛋白含有同源异型盒蛋白特有的4种结构域KNOX1、KNOX2、ELK 和Homeobox_KN。系统进化分析将瓠瓜KNOX基因分为KNOX Class Ⅰ和KNOX Class Ⅱ 2大类群,2个类群又可进一步分为5个分支,其中Class Ⅰ-C为瓠瓜特有的进化分支。KNOX基因启动子区有多个激素响应元件和植物生长相关元件。组织表达分析发现,瓠瓜KNOX基因具有不同的表达模式,KNOX Class Ⅰ类基因表达具有组织特异性,在根、茎和果实中表达量较高,在其余组织中表达量较低或不表达,其中Lsi04G014450在根和茎中表达量最高,Lsi11G006380在果实中表达量最高;KNOX Class Ⅱ类基因在所有组织中均有较高表达。【结论】瓠瓜KNOX基因家族有12个成员,分布于6条染色体上,在进化关系上可分为5组,具有瓠瓜特有的进化分支,在不同组织中的表达具有特异性。     

风味马齿苋野菜酱的研制

以马齿苋、黑豆和苦荞麦等为原料,经过发酵和炒制等工艺开发出了一种风味马齿苋野菜酱。以感官评分为指标,通过单因素试验和正交试验确定了干马齿苋的蒸制时间为10 min,大豆油用量为40 g,白砂糖用量为3.55 g,同时确定了马齿苋野菜酱的最佳配方。在此条件下制备的马齿苋酱风味浓郁、无异味;颜色呈暗红色、明亮,口感酸甜适口;汁液均匀、无分层和沉淀。     

氮磷钾配合施用对冬瓜产量和品质的影响

采用三因子五水平正交旋转组合设计,研究了氮、磷、钾与冬瓜产量和固形物含量的关系。结果显示,在本试验条件下,氮、磷、钾与冬瓜产量和固形物含量呈曲线相关,一定范围内施用能显著提高冬瓜产量和固形物含量,效应大小为氮>钾>磷;氮钾间存在显著的互作关系。最佳施肥量为667 m2施纯N 31~33 kg、P2O517~21 kg、K2O 29~32 kg。     

Start-Timing for Calcium Chloride Spray Programs Influences Fruit Calcium and Bitter Pit in ‘Braeburn’ and ‘Honeycrisp’ Apples

Early-season sprays of calcium chloride (CaCl₂) have been reported to sometimes be more effective than later-season sprays for controlling bitter pit in apple (Malus × domestica Borkh.). We conducted a two-year study examining the influence of start-timing of CaCl₂ spray programs on fruit Ca concentrations and at-harvest bitter pit incidence in ‘Braeburn’ and ‘Honeycrisp’ apples in Washington State, USA. Six biweekly sprays of CaCl₂ were applied starting in mid-May (early-start), mid-June (mid-start, the normal commercial start timing), or mid-July (late-start) 2002 and 2003. Although leaf marginal necrosis occurred in all of the CaCl₂-treated plots, no spray damage on fruit was observed. All of the CaCl₂ spray treatments consistently reduced bitter pit incidence relative to the unsprayed control treatment and usually but not always increased the Ca concentration of subdermal cortical tissue at harvest. The early and mid-start spray programs produced lower bitter pit incidence than the late-start program in only one of four situations. Fruit Ca concentrations in the control and early-start spray program did not differ. Fruit Ca concentrations in the mid- and late-start spray programs were not different, and often were higher than that of the early-start spray program. Bitter pit incidence for each cultivar was inversely related to fruit Ca concentration. Substituting cortical Ca/potassium (K) or Ca/magnesium (Mg) concentration ratios for Ca concentration failed to substantially improve and usually degraded the correlations with bitter pit incidence. The results confirm that starting CaCl₂ spray programs in June sometimes is more effective at controlling bitter pit that delaying the start of the spray program until July. The later season sprays tend to be more effective at increasing fruit Ca concentration. There appears to be no detectable advantage for starting spray programs earlier than June. Applying CaCl₂ sprays throughout the growing season, starting sometime in June, appears to be the most economical and effective spray management practice for maximizing fruit Ca and minimizing risk of bitter pit development.     

苦瓜新品种冠春3 号的选育

冠春3 号是以材料327 作母本,以材料63 作父本配制成的苦瓜一代杂种。植株生长势旺盛,早熟,主侧蔓均可结果。主蔓第1 雌花节位为第8～10 节。瓜长棒形,瓜长28～35 cm,横径5～7 cm,肉厚1.0～1.2 cm,单瓜质量450～600 g。每667 m² 产量3 000～3 500 kg,田间对白粉病、疫病和枯萎病的抗性强于对照蓝山长白和春秋王,适宜四川、湖南、江西等地区种植。     

Effect of vegetable fibre on post prandial glycemia

Effects of feeding different levels of vegetable fibre to normal and non-insulin dependent diabetics were studied. Influences of a control diet (diet with no vegetable fibre) and a purified fibre diet (Isapgol) were compared to results achieved with different levels of several vegetables. A negative correlation between the level of fibre and blood glucose levels in terms of mean percent peak rise, AUC, and per cent glycemic response was shown. Bitter gourd was more effective than the leafy vegetables. Even though the trend in post prandial glucose levels was same for both normal and diabetic subjects, the metabolic response varied significantly between the two groups.