In vitro Regeneration of First-generation Inbred Progenies of Cucurbita pepo L. Double Haploids

Using seeds of inbred progenies of Cucurbita pepo L. DH12-11409 double haplolds as experimental materials, the effects of different hormone combinations, explant types and seedling ages on adventitious bud regeneration and rooting of C. pepo L. were investigated. According to the results, inoculating cotyledonary nodes of yellow-green cotyledons from 5-d-old C. pepo L. double haploids to MS ＋ 30 g/L Suc ＋ 8 g/L Agar ＋ 2.0 mg/L 6-BA ＋ 0.1 mg/L NAA led to the best results with the induction frequency of 90.0% and differentiation coefficient of 8.5. MS medium with addition of 0.05 or 0.1 mg/L NAA led to the highest rooting rate. Regenerated seedlings with 5 - 6 true leaves exhibited the highest survival rate of 90.0%, which was the optimal period for domestication and transplanting of regenerated seedlings. This study laid a solid foundation for high-efficiency utilization of heterosis of C. pepo L.

Study the Effect of Different Levels of Zucchini (<i>Cucurbita pepo</i>L.) on the Biological Indicators for the Prevention of Cardiovascular Disease in Rats Fed High-Fat Diets

The effects of fresh zucchini on nutritional status, and biological indicators for the prevention of cardiovascular disease in rats fed high-fat diets investigated in this study. Thirty Sprague Dawley rats were randomly divided into two main groups the first, negative control group Co (-) (n = 6), fed basal diet, The second group (n = 24) fed high-fat diet (containing basal diet + 5% tallow + 1% cholesterol + 0.02% bile salt). This group was divided into four subgroups each group 6 rats: group positive control co (+) fed high-fat diet only, group 1 (G (1)) fed high-fat diet plus 10% zucchini, group 2 (G (2) fed high-fat diet plus 15% zucchini and group 3 (G (3)) fed high-fat diet plus 20% zucchini. The levels of serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured after eight wk. of experimental treatment. The pathologic changes of the heart, spleen and kidney were evaluated. SPSS, one way ANOVA was used to analyze the results. The results indicated that the mean values of body weight gain (BWG) and feed efficiency ratio (FIR) in G (2) and G (3) showed significant decrease compared to co (-), co (+) and G 1. The results showed that in groups (G1, G2 and G3) the relative weight of heart had significant increase when compared with control negative group. But liver and spleen weight had no significant difference when compared with control negative and positive group, the levels of TC, TG and LDL-C were significantly increased in co (+) (P < 0.05) Compared to co (-), all groups fed on high fat diet containing different levels of zucchini (10%, 15% and 20%) had significant decrease in TC and LDL-C compared with co (+), also G2 and G3 had improve significant in HDL-C when compared with co. (+). The groups fed on zucchini give results similar to group co. (-). The best treatment was zucchini (15% and 20%) which had lowest values of total lipid cholesterol and LDL-C, and the best values of HDL-C, HDL-C/TC % for all groups fed on high fat diet and zucchini increased non significantly (p ≤ 0.05) the HDL-C/TC % index compared to group co. (+). while, G2 and G3 gave significant decrease in LDL-C/HDL-C ratio compared to group co. (+). Morphologic changes of heart, spleen and kidney revealed that groups G2 and G3 had a similar preventive effect against CHD in this experimental model. In conclusion, results showed that zucchini had similar potential to attenuate CHD-related parameters in a mild oxidative stress induced by high-fat diet in rats.

QTL analysis of early flowering of female flowers in zucchini(Cucurbita pepo L.)

Early flowering promotes early maturity, production, and the capacity to counteract biotic and abiotic stresses, making it an important agronomic trait in zucchini. The present study demonstrated that the zucchini inbred line ‘19’ consistently flowered early, taking significantly fewer days to bloom the first female flower(DFF) than the inbred line ‘113’. Genetic analysis revealed that DFF, an inheritable quantitative trait, is controlled by multiple genes. Based on the strategy of quantitative trait locus(QTL) sequencing(QTL-seq) combined with linkage analysis, three QTLs for DFF were identified on chromosomes 4, 11, and 20. This study used additional F2 populations grown under different environmental conditions for QTL mapping analysis of DFF with insertion/deletion(InDel) markers to validate these results. Using the composite interval mapping(CIM) method of R/qtl software, we only identified one major locus under all environmental conditions, located in a 117-kb candidate region on chromosome 20. Based on gene annotation, gene sequence alignment, and qRT-PCR analysis, we found that the Cp4.1LG20g08050 gene encoding a RING finger protein may be a candidate gene for the opposite regulation of early flowering in zucchini. In summary, these results lay a foundation for a better understanding of early flowering and improving early flowering-based breeding strategies in zucchini.

The Effects of Simultaneous Application of Different Organic and Biological Fertilizers on Quantitative and Qualitative Characteristics of Cucurbita pepo L,

Understanding the relations and interactions between ecosystem components and plants is crucial for sustainable production of medicinal plants. To study the effect of simultaneous application of organic and biological fertilizers on yield and yield components of zucchini squash, split plot arrangement of factors based on randomized complete block design with three replications were used during 2009-2010 growing season. The mainplot factors were the type of organic fertilizers, including： （1） cow manure; （2） sheep manure; （3） chicken manure; （4） vermicompost; and （5） control. The subplot factors were the biofertilizes （Nitragin, containing Azotobacter sp., Azospirillum sp. and Pseudomonas sp.） utilization. The results showed the positive but non-significant effect of organic and biological fertilizers on yield and yield components of zucchini squash. Amongst the organic fertilizers, cow and chicken manure, have superiority compared to others. The highest seed oil and protein percent was obtained with application of chicken manure, however there was no significant difference between treatments in seed oil percent. The positive effect of organic and biological fertilizers on seed yield was higher than fruit yield. At a glance, application of cow manure solely was better than its application with nitragin. Nitragin application has no significant effect on some traits when utilized with sheep manure and vermicompost.

Dependence of Pumpkin Yield on Plant Density and Variety

Pumpkins (Cucurbita spp.) are an important specialty vegetable. Field studies were conducted on three pumpkin cultivars characterized with different growth habits to determine the effects of plant population and genotypes on marketable yield. Increasing plant populations from 4780 to 9560 plant per hectare resulted in significantly greater fruit number and yield in both growing seasons and for all tested genotypes. Average fruit weight declined at the higher populations. The response of pumpkin genotypes to different planting densities was genotype (growth habit) dependent since the response was pronounced in large vine types compared to bush type. The phenotypic variation existed among pumpkin genotypes for yield seems to be under genetic control. Foliar application of potassium improved growth and yield of pumpkin plants although the non-significant effect. These results demonstrate that growers may increase pumpkin yield by increasing plant populations.

Fatty Acid Accumulation in Seeds of Three Seed Pumpkin Cultivars

In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developing seeds. The objective of this study was to provide the changes of various fatty acid accumulations in seed oil obtained from the seeds of three pumpkin varieties belonging to the species Cucurbita maxima and Cucurbita pepo. Unsaturated acids(oleic and linoleic) were dominant in various fatty acids, which constituted 38.9%-49.1% and 29.4%-42.7% of the total fatty acids at seed maturity for three pumpkin varieties, respectively, while other fatty acid concentrations except for palmitic acid all did not reach 10%. Different varieties exhibited greater effect on various fatty acid contents and the total fatty acid contents in the seeds of pumpkin rather than the species. On the whole, palmitic acid profiles of the seed oil in three varieties all followed the fluctuant decrease during all the stages of seed development, but palmitoleic acid and the total fatty acid profiles of the seed oil in three varieties were just the opposite. Stearic, oleic and linoleic acid profiles of the seed oil in three varieties all experienced the third pattern that fluctuated during all the stages of seed development, but no significant differences in these three fatty acid concentrations were found from the beginning to the end. Linolenic acid concentrations of three varieties were on the decline and ultimately close to zero. Myristic and arachidic acid profiles of the seed oil followed different trends in three varieties. Among them, myristic and arachidic acid profiles of the seed oil of Yinhui-1 fluctuated downward all the time until seed maturity, but those of 0238-1 and Jinhui-2 completely changed oppositely.

美洲南瓜(Cucurbit pepo)WMV-2抗性遗传及分子标记研究

以美洲南瓜(Cucurbita pepo)抗病自交系‘0504’和感病自交系‘0223’为亲本杂交获得的157个F2单株为材料,研究南瓜对西瓜花叶病毒2号(WMV-2)抗性的遗传规律和分子标记。对亲本、F1及F2苗期接种WMV-2进行抗病性鉴定,结果表明,美洲南瓜对WMV-2的抗性由单隐性基因控制。采用集团分离分析法(BSA)和SSR技术,筛选出与WMV-2抗性基因连锁的标记CMTm157和CMTm158,遗传距离分别为10.9cM和6.2cM,其可以作为南瓜抗WMV-2育种的辅助选择分子标记。

不同CaCl_(2)试剂组合对西葫芦种子低温萌发的影响

以‘春翡翠’西葫芦种子为试材,采用CaCl_(2)溶液、CaCl_(2)+脲基二琥珀酸四钠(HIDS)溶液、CaCl_(2)+黄腐酸(FA)溶液、去离子水(CK)浸种,研究不同CaCl_(2)试剂组合浸种对低温下种子萌发的影响,以期为提高西葫芦抗冷性提供参考依据。结果表明:与对照相比,添加CaCl_(2)的3个处理均可提高西葫芦种子在低温下的萌发能力,表现为CaCl_(2)+FA>CaCl_(2)+HIDS>CaCl_(2)>CK。与对照相比,CaCl_(2)+FA浸种效果最好,浸种后西葫芦种子发芽率、发芽势、发芽指数、活力指数显著提高2.48%、2.48%、1.15%、14.71%;根长、鲜质量、干质量显著增加15.12%、46.47%、13.35%;CaCl_(2)+FA溶液浸种提高了芽苗中渗透调节物质含量及抗氧化酶活性,使芽苗中脯氨酸、可溶性糖、可溶性蛋白质含量、超氧化物歧化酶、过氧化物酶活性分别增加14.52%、180.00%、31.78%、1.52%、53.53%;超氧阴离子自由基、过氧化氢含量分别降低了131.97%、35.83%。综上所述,不同CaCl_(2)试剂组合均可减轻低温对种子萌发的伤害,其中CaCl_(2)与FA组合浸种缓解低温伤害效果最佳。

A Simple Inexpensive Method for the Measurement of Indoleacetamide Hydrolase Activity

Indole-3-acetic acid (IAA) a phytohormon of auxin type is synthesized by different ways in plants and some bacteria (Agrobacteria, Pseudomonas and some others). The enzyme indolylacetamide hydrolase transforms indolylacetamide to IAA mainly in bacteria. However, recently published data showed that some plants can also hydrolyze indolylacetamide into IAA. In order to elucidate the role of indolylacetamide as an auxin precursor in plants and bacteria, productive method of determination of the activity of indoleacetamide hydrolase is necessary. The simple, inexpensive and productive method for the measurement of indoleacetamide hydrolase activity was elaborated based on significant difference between IAAM and IAA in color developed with Salkovski’ reagent. The light absorbance increased during conversion of IAAM to IAA by protein extracts from some plant cells and this increase may be used for quantitative estimation of indoleacetamide hydrolase activity. The method is suitable for fast discovery of indoleacetamide hydrolase activity before planning more complicated analyses and for the analysis of many probes at a short time in physiological and biochemical experiments. A detailed protocol for determination of indoleacetamide hydrolase activity by the elaborated method is described.

利用冬闲田种植美洲南瓜（CucurbitapepoL．）的栽培技术

根据美洲南瓜的栽培特性和广西各地的气候条件，详细介绍了利用冬闲田种植美洲南瓜的栽培技术。

硅对盐胁迫下西葫芦幼苗水分代谢及光合特性的影响

【目的】探究外源硅对盐胁迫下西葫芦幼苗水分代谢及光合作用的保护机制,可为西葫芦抗盐栽培提供理论参考。【方法】以西葫芦品种‘寒绿7042’为试材,通过水培试验,共设置对照、硅处理(0.3 mmol/L Na_(2)SiO_(3)·9H_(2)O)、盐胁迫(150 mmol/L NaCl)、盐胁迫+硅等4个处理,处理10 d后测定幼苗的根系形态和活力,叶片含水量、水势、光合气体交换参数、叶绿素含量、叶绿素荧光参数及根系质膜水通道蛋白基因的表达等指标。【结果】盐胁迫显著抑制了西葫芦幼苗根系的生长,降低了根系活力、叶片含水量、叶片水势和蒸腾作用,还破坏了植株的光合系统,导致净光合速率、气孔导度、叶绿素含量和PSⅡ光化学效率显著降低。外源硅显著改善了盐胁迫下西葫芦幼苗的根系形态,提高了根系活力,并通过促进根系质膜水通道蛋白基因PIP1;2、PIP1;3、PIP1;5、PIP1;7、PIP2;1、PIP2;4、PIP2;6、PIP2;8、PIP2;9和PIP2;12的表达改善植株体内的水分状况,提高叶片含水量和水势,增强蒸腾作用;外源硅还通过提高叶片气孔导度、叶绿素含量、净光合速率、PSⅡ最大光化学效率、PSⅡ实际光化学效率、光化学淬灭系数,降低胞间CO_(2)浓度和非光化学淬灭系数来增强盐胁迫下幼苗的光合作用。【结论】盐胁迫下添加0.3 mmol/L的硅可以有效改善西葫芦幼苗的水分代谢和光合作用状况,从而提高西葫芦幼苗抗盐胁迫能力。

西葫芦嫩瓜皮叶绿素合成代谢与其皮色形成的关联性研究

为了挖掘优异西葫芦(Cucurbita pepo L.)种质资源,提高外观品质优的嫩瓜选择效率,本研究利用色差仪对本单位创制的54份西葫芦自交系进行不同嫩瓜皮色分类,并以其中7份(重点4份)代表性材料为研究对象,对西葫芦嫩瓜皮叶绿素合成代谢与其皮色形成的关联性进行分析。结果表明,叶绿素是决定偏白色、浅绿色、翠(青)绿色、绿色和深绿色西葫芦嫩瓜皮色的主要色素。其中,叶绿素a含量占总含量的49.20%~60.58%,是决定嫩瓜皮色深浅的主要因素。颜色最鲜艳且更加偏绿色的翠(青)绿色嫩瓜皮材料,其色度值(C)显著大于其他皮色,而叶绿素a/叶绿素b和红绿值(a*)分别显著大于和小于偏白色、浅绿色和深绿色皮色。深绿色、翠(青)绿色和偏白色嫩瓜皮叶绿素合成存在胆色素原转化为尿卟啉原Ⅲ和粪卟啉原Ⅲ转化为原卟啉IX两个受阻点,且后一转换阶段是导致偏白色和翠(青)绿色嫩瓜皮叶绿素合成受阻、叶绿素含量骤降的主要原因。叶绿素合成减弱与叶绿素代谢中的叶绿素酶降解活性增强以及抗氧化酶中的超氧化物歧化酶和过氧化氢酶活性减弱之间呈显著相关,这也证明了嫩瓜皮偏白色的成因。超氧化物歧化酶和过氧化氢酶活性与嫩瓜皮叶绿素含量呈显著相关,这两种酶延缓了翠(青)绿色和深绿色嫩瓜皮叶绿素含量降低速率。本研究结果为深入解析不同嫩瓜皮色,特别是翠(青)绿色嫩瓜皮呈色机理以及挖掘、利用相关优异特异资源提供了理论依据和技术支撑。

含聚天冬氨酸微生物肥料中养分比例对西葫芦生长的作用初探

针对国内温室西葫芦生产过程中存在的盲目施用肥料而造成的瓜菜产量和品质的降低问题进行了研究。以河北培根生物科技有限公司生产的微生物肥料(添加聚天冬氨酸)为供试肥料,以N、P_(2)O_(5)、K_(2)O不同养分比例设置试验处理(T1、T2、T3)、普通复合肥料(N 15%、P_(2)O_(5) 15%、K_(2)O 15%)作为CK处理进行了相关试验,通过对西葫芦不同生物阶段的多个指标进行综合分析,结果发现,在试验范围内T1(N 16%、P_(2)O_(5) 9%、K_(2)O 20%)处理效果最佳;所试验的肥料促进西葫芦的营养生长、促进开花坐果、加快果实发育速度,还能提高瓜菜外观品质、可溶性糖含量和V_C含量,显著提高了产量和经济效益。

低温胁迫对不同西葫芦品种幼苗生长与生理特性的影响

在昼/夜温度为10℃/5℃的低温胁迫下,对‘特早’、‘早青’、‘冬宝’3个西葫芦(Cucurbit pepoL.)品种的幼苗生长和生理生化指标的变化规律进行研究。结果表明,随着低温处理时间的延长,幼苗单株叶面积、单株干重均有一定程度下降,叶绿素总含量也呈下降趋势;各品种的根系活力显著下降,电导伤害率均明显升高;丙二醛含量在处理9 d时有所下降但整体呈现缓慢上升的趋势,脯氨酸含量呈现逐渐上升的趋势,且处理6 d是脯氨酸和丙二醛两指标测定的理想时期;处理幼苗的POD活性呈"V"字形变化趋势,抗寒性强的品种酶活性也较高,CAT和SOD活性则呈现出先上升后下降的趋势,三者活性均显著高于相应对照,且以处理6 d时酶活性受影响最大。各测定指标间表现出一定的交叉适应和协调性。研究发现,西葫芦耐冷性强弱可根据幼苗电解质渗透率结合根系活力或干物质积累来综合评判,品种‘冬宝’对低温具较强耐受性。

西葫芦未受精胚珠离体培养条件的优化及胚囊植株的产生

目的建立西葫芦离体雌核发育高频植株再生体系,以加速自交系选育,有效缩短西葫芦杂种一代育种周期。方法将西葫芦未受精胚珠接种至附加2,4-D、NAA、BA的N6培养基上可形成胚状体,该胚状体转接至无激素的N6培养基上可形成再生植株。结果试验共获得120棵再生植株(R0),其中41株因生活力低下死亡,8株用于摸索移栽方法死亡,71株移栽成活且生长正常,其中42株性状表现符合二倍体特征且育性正常,已有10株获得自交果实及种子,其余29株育性异常。试验结果表明,胚珠发育时期、培养基、供体基因型及供体栽培季节等均显著影响胚状体诱导频率。结论胚状体起源于胚囊成员细胞,再生植株为胚囊植株。试验筛选出3种诱导频率较高的培养基;以开花前1日及当日的胚珠诱导频率较高;秋播材料诱导效果最好。

低温对不同西葫芦自交系花粉发芽力的影响

在不同开花温度(FT)和发芽温度(GT)组合处理下,测定了西葫芦14个自交系的花粉发芽率。结果表明:①随FT和GT的降低,西葫芦花粉发芽力下降。正常GT24℃下平均花粉发芽率在48%以上,GT15℃下为30%左右,GT9℃下发芽率极低,接近零,FT和GT的影响都达到极显著,但GT影响较大,FT和GT交互作用不显著。②不同的FT和GT组合下,自交系间花粉的发芽率除FT15℃/GT24℃下差异不显著,其他FT(15℃、12℃、9℃)和GT(24℃、18℃、15℃、12℃、9℃)的各组合温度下,都达到了极显著差异。③在FT9℃/GT12℃培养时,自交系间方差分析的F值最大,且变异系数最大,花粉发芽力的差异达到最大,说明该温度组合可作为鉴定西葫芦不同品系(种)耐冷性的适宜花粉培养温度。

温度和湿度对西葫芦贮藏过程中品质的影响

研究了室温(28～32℃)和10℃条件下不同湿度(低湿、饱和湿度)对西葫芦(Cucurbita pepo L.)采后贮藏品质的影响。结果表明,随着贮藏时间的延长,西葫芦表皮颜色趋于黄化,水分含量下降,萎蔫和腐烂程度加深。低温和饱和湿度处理可以延缓颜色指数、萎蔫指数和腐烂指数的上升以及叶绿素、维生素C和可溶性蛋白含量的下降,减少西葫芦瓜肉和表皮水分的损失,较好地保存西葫芦的外观和营养品质。

西葫芦子叶花芽分化时内源激素、多胺含量的变化

西葫芦子叶于附加 1.0mg/LKT(激动素 )MS(Murashige ,Skoog)培养基中培养 ,明显提高了子叶的花芽分化率 ,分析其内源激素、多胺含量的动态变化 ,发现经KT处理组的子叶在花芽分化时 ,其内源GA1/3 (赤霉素 )含量降低 ,而ZRs(玉米素核苷 )含量显著增加 ,表现出高的ZRs/GA1/3 比值 .花芽分化时 ,子叶内源Spm(精胺 )、Spd(亚精胺 )含量剧增 ,其中经KT处理组的子叶 ,其内源Spd含量较对照组增加 2倍多 ,而Put(腐胺 )含量在萌生不定根和营养芽时急剧增加 ,但到花芽分化时又突然下降 .表明内源ZRs、Spd含量高与ZRs/GA1/3

西葫芦穴盘育苗潮汐灌溉技术研究

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