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.

美洲南瓜(Cucurbita pepo)种皮苯丙氨酸解氨酶基因克隆与表达分析

【目的】克隆有壳美洲南瓜种皮PAL基因(CP-PAL),研究PAL基因在有壳和裸仁美洲南瓜种皮发育过程中的表达特性,为揭示美洲南瓜种皮发育机理及木质素积累在南瓜种皮发育中的作用等方面提供理论依据。【方法】利用RT-PCR,结合RACE技术克隆CP-PAL的全长序列并进行生物信息学分析;利用实时荧光定量PCR技术,采用2-△△Ct方法对种皮发育过程中PAL基因的表达进行分析。【结果】CP-PAL序列全长为1 720 bp,含有一个1 359bp的ORF,114 bp 5′端非翻译区、236 bp 3′端非翻译区及11 bp polyA结构,可编码452个氨基酸,分子量为48.86 kD,等电点为6.55,原子总数为6 885个,分子式为C2158H3449N607O657S14。通过BLASTX比对表明CP-PAL核苷酸序列及其氨基酸序列与黄瓜PAL核苷酸及其氨基酸序列的相似性最高。CP-PAL包含PAL-HAL、PLN02457及phe_am_lyase 3个结构域及酶活性中心序列(GTITASGDLVPLSYIA),属于Lyase_I_Like超家族。CP-PAL不具有导肽及信号肽,为非跨膜蛋白,可能定位于细胞质及内质网上,属可溶性蛋白。CP-PAL蛋白含有4个酪蛋白激酶Ⅱ识别位点、6个蛋白激酶C识别位点、12个豆蔻酰化位点及2个糖基化位点。此外,分析可知CP-PAL有18个丝氨酸磷酸化位点、6个苏氨酸磷酸化位点及5个酪氨酸磷酸化位点。无规则卷曲是CP-PAL蛋白二级结构中最大量的结构元件,α-螺旋和延伸链分散于整个蛋白质中,且N-末端以无规则卷曲形式存在,C-末端以延伸链形式存在。CP-PAL氨基酸序列同挑选的其他14种植物的PAL氨基酸序列进行多重序列比较,发现功能区域的氨基酸序列较为保守,N-端的差异最大。系统进化树分析表明CP-PAL和黄瓜PAL蛋白的亲缘关系最近。CP-PAL蛋白三级结构以α-螺旋为主要结构元件,β-转角和无规则卷曲较少。实时荧光定量PCR分析表明PAL基因在有壳和裸仁美洲南瓜种皮发育中呈现反向对应的变化趋势:有壳美洲南瓜种皮PAL基因在自交授粉20 d后表达量增加,而裸仁美洲南瓜种皮PAL基因在20 d后表达量下降。整个种皮发育过程中,PAL基因在裸仁美洲南瓜中的表达量低于其在有壳美洲南瓜中的表达量。【结论】从有壳美洲南瓜种皮中克隆得到与木质素合成相关的PAL基因,该基因可能通过参与调控种皮木质素的合成从而影响美洲南瓜裸粒品种的种皮发育。

美洲南瓜(Cucurbita pepo)种皮发育形态观察及其相关酶活性测定

采用组织整体染色和石蜡切片相结合的方法对美洲南瓜有壳品种04LAg-26-2和无壳品种04LAg-26-28种皮发育形态结构比较观察。结果表明,有壳美洲南瓜种皮是由表皮层、下皮层、厚壁组织层、软组织层和绿色组织层构成,无壳裸仁南瓜的形成主要是授粉后18 d种皮发育过程中厚壁组织中的细胞变形、瓦解,缺少木质素的积累而导致了下皮层、厚壁组织层的缺失;对2个品种的种皮、叶片、叶柄和瓜囊不同组织中木质素合成相关酶活性测定结果表明,无壳品种04LAg-26-28在授粉18 d后,种皮中苯丙氨酸解氨酶(PAL)、肉桂酸-4-羟基化酶(C4H)、4-香豆酸-辅酶A连接酶(4CL)、肉桂醇脱氢酶(CAD)和过氧化物酶(POD)活性明显降低,而叶片、叶柄和瓜囊中这几种酶活性在授粉18 d后,呈逐渐增加的趋势。

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.

Use of Cucurbita pepo Oil to Fight against the UV Action on the Skin

Skin aging is a process most often attributed to UV [1] and also to the use of creams and other cosmetic products low in antioxidant compounds [2]. Photochemically stable pepo Cucurbita oil can be used as an exogenous cosmetic supplement due to its high antioxidant content. Incorporated in an agar, media containing a synthetic melanin solution with added pumpkin oil are subjected to UV light, the aging thus modeled is followed by the measurement of photoresistance values correlated with chemical and spectrophotometric analyses. This study confirms that pumpkin oil is highly effective in protecting the skin, especially the most sensitive skins such as babies’ skin [3] by reinforcing the action of melanin and also that of albinos without melanin. Indeed its SPF (Significant Sun Protection Factor) index estimated during this work is very consistent, i.e. more than 22% of UVB (280 - 315 nm) radiations are suppressed.

Direct Organogenesis from Cotyledonary Node Explants of Cucurbita pepo (L.)—An Important Zucchini Type Vegetable Crop

Cotyledonary node explants from 3 - 5-d-old seedling derived explants of Cucurbita pepo (L.) produced multiple shoots in Murashige and Skoog (MS) salts B5 vitamins containing medium in the presence of N6-benzylamino-purine BAP 1 mg/L + Thidiazuron TDZ 0.05 mg/L. After 4 weeks explants were subcultured to medium containing MS salts B5 Vitamins BAP 0.5 mg/L, Gibberellic acid GA3 1 mg/L and L-Glutamine 15 mg/L. Periodic excision of regenerated shoots from the explants increased shoot efficiency during subculture. The combination of L-Glutamine with BA and GA3 significantly increased the shoot proliferation. Elongated shoots were excised from shoot clumps and transferred to rooting medium containing indole-3-butyric acid (IBA, 1.0 mg/L). The rooted plants were hardened in small pot containing standardized garden soil, well developed plant transferred to greenhouse and survival rate was 85%.

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.

Valorization of Cucurbita pepo Seed Oil in Soap Production

The present study was conducted with the aim of extracting and characterising Cucurbita pepo seed oil and then producing soap with important dermatological properties. The physico-chemical results of the Cucurbita pepo seed oil after extraction were satisfactory and indicate that the oil obtained contains long-carbonaceous fatty acids. The production of the soap was based on the realisation of a saponification reaction by reflux heating between the extracted oil and a solution of soduim hydroxyde 7M for one hour. The soap obtained is characterised by the following physico-chemical parameters: salt content, alkali content, pH, and humidity;which meet ISO 684-1974 standards. The antibacterial parameters of the soaps S1, S2, S3, S4, S5 and S6 were determined by the Agar Diffusion test using the well method and these soaps showed an interesting antibacterial activity against the germs pseudomonas aeruginosa and staphylococcus aureus. Soaps based on Raffia sese oil (kolo oil) and Elaesis guineensis oil (palm oil) have also been synthesized for comparison with soap obtained from Cucurbita pepo seed oil.

北方早春棚室西葫芦嫁接育苗栽培技术

为了提高西葫芦的产量和品质,满足市场需求,根据多年的从事棚室栽培技术经验,总结了北方棚室西葫芦嫁接育苗栽培技术,以供广大种植户参考。

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。

应用SRAP标记分析金丝瓜(Cucubita pepo L.)种质资源遗传多样性与亲缘关系

本研究应用SRAP分子标记技术对56份金丝瓜和32份南瓜属(包括美洲南瓜、中国南瓜、印度南瓜)种质资源遗传多样性与亲缘关系进行分析。结果表明:(1)从285对SRAP引物中共筛选出50对多态性引物对供试品种基因组DNA进行PCR扩增,获得713条清晰可辨的标记,其中多态性条带634条,多态性比率达88.92%,说明南瓜属种间遗传多样性较丰富;(2)在56份金丝瓜品种中,共扩增出586条清晰可辨条带,多态性条带350条,多态性比率为59.73%,说明金丝瓜品种间的遗传相似性较高;(3)通过分子聚类分析可将供试金丝瓜品种划分为5个亚类群。金丝瓜与美洲南瓜的亲缘关系较近,与中国南瓜的亲缘关系较远,而与印度南瓜的亲缘关系最远;分子聚类分析结果证实金丝瓜为美洲南瓜的一个变种。

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。

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。

西葫芦NCED基因家族鉴定及其响应干旱胁迫分析

NCED基因家族成员在调节植物响应干旱胁迫中发挥着关键作用,该研究通过生物信息学技术分析NCED在西葫芦基因组中的分布、结构及进化,研究家族成员在不同组织中的表达特异性及其对10%PEG 6000模拟干旱、0.1 mmol·L-1ABA激素和自然干旱胁迫的响应,以解析NCED基因家族的生物学功能。结果表明:(1)从西葫芦全基因组中鉴定出6个NCED家族基因(CpNCED1~6),且6个基因均不含内含子、分别分布于西葫芦的1、10、12、14、19和20号共6条染色体上。(2)理化性质分析发现,CpNCED1~6蛋白长度为569~590 aa,理论分子量在62.64~65.54 kD之间。(3)蛋白保守元件分析显示,除CpNCED3蛋白在遗传进化过程中出现3个基序(motif 12、motif 13和motif 15)的缺失外,其余5个蛋白都有完整的16个motif保守基序,且分布在600个氨基酸以内,同时大部分NCED蛋白序列保守性较高。(4)顺式作用元件分析显示,西葫芦CpNCED1~6基因均含ABRE、W box、MBS、P-box、TCA-element、CGTCA-motif、TGA-element和TGA-box等潜在的干旱胁迫响应元件。(5)qRT-PCR分析表明,CpNCED1~6基因在西葫芦不同组织中的表达具有组织特异性,其中,CpNCED4和CpNCED1在茎中的表达量显著高于其他4个基因,CpNCED2、CpNCED4、CpNCED6在花中的表达显著高于其余3个基因且CpNCED2表达量最高,CpNCED1~6在果实和叶中的表达量均相对较低;与对照组相比,CpNCED1~6受模拟干旱、ABA激素和自然干旱胁迫均上调表达;伴随干旱胁迫的产生,叶片中脱落酸(ABA)含量逐渐升高,暗示CpNCEDs在西葫芦干旱胁迫响应与ABA的生物合成过程中发挥着正向调控作用。研究发现,6个CpNCED1~6基因与西葫芦干旱胁迫响应密切相关,且对西葫芦干旱胁迫的响应以及ABA生物合成具有重要作用,尤其以CpNCED2和CpNCED4基因的作用更为明显。

内蒙古籽用西葫芦种子病毒鉴定及消毒效果评价

【目的】对内蒙古籽用西葫芦种子病毒进行鉴定,明确其种子携带病毒的情况;对带毒种子进行不同消毒处理,筛选出有效的消毒方法,为内蒙古地区籽用西葫芦病毒病的防治提供依据。【方法】采集具有典型病毒病症状的金粒1号、金丰娇子、瑞丰9号、金丰光板、希望9号、晶莹118籽用西葫芦种子,对其进行反转录PCR检测及病毒序列分析对比,采用温汤、干热、磷酸三钠、盐酸、药剂等对带毒种子进行消毒处理,并采用实时荧光定量PCR技术检测带毒量,测定消毒种子的发芽率和发芽势。【结果】采用反转录PCR扩增,在6个品种籽用西葫芦种子中检测到黄瓜花叶病毒(cucumber mosaic virus,CMV)、小西葫芦黄化花叶病毒(zucchini yellow mosaic virus,ZYMV)、西瓜花叶病毒(watermelon mosaic virus,WMV)。通过5种处理方法对籽用西葫芦种子进行消毒,结果表明,温汤、干热、磷酸三钠、盐酸和药剂处理均能不同程度地降低籽用西葫芦种子带毒量,其中磷酸三钠处理对CMV的消毒率为99.68%,药剂处理对ZYMV的消毒率为99.74%,温汤处理对WMV的消毒率为99.89%,且不影响种子的发芽率和发芽势。【结论】内蒙古籽用西葫芦种子病毒病病原为CMV、ZYMV、WMV,且存在复合侵染。磷酸三钠处理对籽用西葫芦种子病毒病消除效果最佳。

西葫芦CpWRKY2基因的分离、鉴定及其对非生物胁迫分析

为了解西葫芦(Cucurbita pepo)的WRKY2的功能,通过转录组测序技术从叶片中分离到1条长度为1 071 bp的c DNA,并对其进行序列分析。结果表明,该序列包含1个840bp的开放读码框,预测编码279个氨基酸,与中国南瓜(Cucurbita moschata,XM_023091218.1)的WRKY核苷酸序列相似性为98.51%,命名为CpWRKY2 (GenBank登录号:XM_023676898.1)。CpWRKY2定位于细胞核内,CpWRKY2蛋白包含有1个保守的WRKY结构域(第201~267位),206~266位为WRKY蛋白DNA结合区域,锌指结构域(第232~264位)为C2H2型,且含有1个保守RTGHARFRRAP (第76~86位)氨基酸序列,属于典型的Ⅱd亚类WRKY家族蛋白。CpWRKY2基因上游启动子区域(ATG前的1 513 bp的序列)含有ARE、ABRE、MBS、TCrichrepeat和W-box等可能的胁迫响应顺式作用调控元件。CpWRKY2具有组织表达特异性,在花中表达量最高,其次为根和茎,在叶片和果实中的表达量较低。经5℃、10%PEG 6000模拟干旱胁迫,0.1 mmol/L ABA、50 mmol/L ETH、10 mmol/L SA和50 mmol/L MeJA处理后叶片中CpWRKY2均出现上调表达,因此,推测CpWRKY2基因参与了西葫芦不同非生物胁迫的防御反应。

美洲南瓜Dof基因家族鉴定与表达模式分析

DNA结合单锌指(DNA binding with one finger,Dof)是植物所特有的转录因子,主要参与调控植物的生长发育、抗逆和品质等生命活动过程。为了鉴定美洲南瓜Dof基因家族成员和探究其表达模式,从全基因组水平筛选和分析了美洲南瓜CpDof家族成员、基因结构、蛋白保守基序和亲缘关系等,同时,通过转录组和荧光定量技术比较了不同成员在美洲南瓜中的时空表达与果实发育表达特性。结果表明,在美洲南瓜中存在58个Dof基因并广泛分布于全基因组;功能域Motif 1存在于所有的Dof基因中;其启动子序列中含有光响应、激素响应和防御应激等顺式作用元件;Dof基因在美洲南瓜中具有组织表达特异性和时空表达特异性。基于转录组和荧光定量验证结果,表明CpDof7、CpDof30和CpDof42等基因与美洲南瓜356和296果实发育密切相关。以上结果为进一步克隆和解析南瓜属Dof基因功能提供了有力支撑。

高能电子束辐照对金丝绞瓜贮藏特性的影响

目的:确定高能电子束辐照处理金丝绞瓜的最优剂量,改善金丝绞瓜的贮藏特性。方法:分别以0.3,0.4 kGy和0.5 kGy剂量的高能电子束从两面处理金丝绞瓜。结果:0.4 kGy高能电子束辐照处理使金丝绞瓜腐烂率降低16.18%,其总酚含量维持较高水平,可溶性固形物含量降低,丙二醛积累量减少,呼吸强度、失重率、色彩饱和度、可滴定酸和过氧化物酶活性均与对照瓜无显著差异(P>0.05),在此剂量下,超氧化物歧化酶的活性高峰是对照瓜的1.14倍,瓜丝细胞超微结构完整;在贮藏120 d时,脆度、葫芦巴碱含量和苯丙氨酸解氨酶活性分别是对照瓜的1.58,3.34倍和1.84倍。结论:0.4 kGy是适宜的高能电子束辐照剂量,有望将其用于金丝绞瓜的贮藏保鲜。

美洲南瓜抗白粉品种筛选及其与生理指标的相关性

【目的】建立美洲南瓜抗白粉病评价指标,筛选抗性较强的品种。【方法】试验以14个美洲南瓜品种为试材,基于病情指数、抗性划分标准和生理指标测定了不同南瓜品种对白粉病的抗性效果,并筛选出抗病品种。【结果】筛选出抗病品种1个、中抗品种5个、感病品种6个和极感品种2个。抗病品种叶片中脯氨酸(Pro)含量、苯丙氨酸解氨酶(PAL)含量、丙二醛(MDA)含量、蜡质含量均高于感病品种,可溶性蛋白(SP)含量低于感病品种,其中蜡质含量、MDA含量、Pro含量、PAL含量与病情指数呈负相关关系,SP含量与病情指数呈正相关关系。【结论】蜡质含量、SP含量、Pro含量、PAL含量、MDA含量均可作为美洲南瓜白粉病抗性品种抗性评价指标。根据病情指数和生理生化指标,JPG2015-44和JPG2015-12为美洲南瓜白粉病抗病品种。