An acorn squash (Cucurbita pepo ssp. ovifera) fruit and seed transcriptome as a resource for the study of fruit traits in Cucurbita

Acorn squash(Cucurbita pepo)is an iconic fall vegetable in the United States,known for its unique fruit shape and also prized for its culinary properties.Little is known about the metabolism that underlies the development of fruit quality attributes such as color,sweetness,texture and nutritional qualities in acorn squash,or any other winter squash grown worldwide.To provide insight into winter squash fruit and seed development and add to the genomic resources in the Cucurbita genus,RNA sequencing was used to generate an acorn squash fruit and seed transcriptome from the cultivar Sweet REBA at critical points throughout fruit development.141838600 high-quality paired-end Illumina reads were assembled into 55949 unigenes.85%of unigenes with predicted open reading frames had homology with previously identified genes and over 62%could be functionally annotated.Comparison with the watermelon and cucumber genomes provided confirmation that the unigenes are full-length and comprehensive,covering an average of 90%of the coding sequence of their homologs and 72%of the cucumber and watermelon exomes.Key candidate genes associated with carotenoid and carbohydrate metabolism were identified toward a resource for winter squash fruit quality trait dissection.This transcriptome represents a major advance in C.pepo genomics,providing significant new sequence information and revealing the repertoire of genes expressed throughout winter squash fruit and seed development.Future studies on the genetic basis of fruit quality and future breeding efforts will be enhanced by tools and insights developed from this resource.

Molecular and biological characterization of melon-infecting squash leaf curl China virus in China

It has been reported that squash leaf curl China virus(SLCCNV)infects some Cucurbitaceae crops except for melon(Cucumis melo L.).A new disease of melon exhibiting severe leaf curl and dwarfing was observed in Hainan Province of China.In this study,the pathogen was identified as SLCCNV through biological and molecular characterization.The isolate(SLCCNV-HN)possess a bipartite genome,DNA-A(HM566112.1)with the highest nucleotide identity(99%)to SLCCNV-Hn(MF062251.1)pumpkin and SLCCNV-Hn61(AM260205.1)squash isolates from China,whereas DNA-B(HM566113.1)with the highest nucleotide identity(99%)to SLCCNV-Hn(MF062252.1).Phylogenetic analyses based on the full-length SLCCNV-HN DNA-A and-B sequences indicated that SLCCNV-HN melon isolate is clustered with SLCCNV-Hn pumpkin,SLCCNV-Hn61 and SLCCNV-SY squash isolates from southern China,forming an independent cluster.Infectious clone of SLCCNV-HN was constructed and the melon plants were inoculated and the infection rate is 100%,the systemic symptoms in melon showed identical to those of melon plants infected in fields.Additionally,melon plants transmission of this virus by Bemisia tabaci with a transmission rate of 95%(19/20)showed leaf curl and dwarf symptoms 15 days post transmission,thereby fulfilling Koch’s postulates.Analysis of genomic organization and phylogenetic trees indicated that SLCCNV-HN melon isolate belongs to the Begomovirus genus.To the best of our knowledge,this is the first characterization of meloninfecting SLCCNV through its genome,infectious clone and transmission.

Comparative analysis of Cucurbita pepo metabolism throughout fruit development in acorn squash and oilseed pumpkin

Both the fruit mesocarp and the seeds of winter squash can be used for consumption,although the focus of breeding efforts varies by cultivar.Cultivars bred for fruit consumption are selected for fruit mesocarp quality traits such as carotenoid content,percent dry matter,and percent soluble solids,while these traits are essentially ignored in oilseed pumpkins.To compare fruit development in these two types of squash,we sequenced the fruit transcriptome of two cultivars bred for different purposes:an acorn squash,‘Sweet REBA’,and an oilseed pumpkin,‘Lady Godiva’.Putative metabolic pathways were developed for carotenoid,starch,and sucrose synthesis in winter squash fruit and squash homologs were identified for each of the structural genes in the pathways.Gene expression,especially of known rate-limiting and branch point genes,corresponded with metabolite accumulation both across development and between the two cultivars.Thus,developmental regulation of metabolite genes is an important factor in winter squash fruit quality.

Isolation and Identification of Squash Leaf Curl China Virus in Zucchini

[Objectives]In 2019,virus diseases occurred widely on zucchini planted in Shandong Province.The disease symptom was different from previous reports.This study aimed to identify the pathogen causing the zucchini virus disease.[Methods]Ten diseased zucchini leaves were collected in the field and used as materials for PCR and sequencing.[Results]PCR detection and sequencing showed that the nucleotide sequence of the amplified fragment had the highest identity with the squash isolate of squash leaf curl China virus(SLCCNV)(MW389919.1)in Guangdong Province.Primers were further designed for amplifying the full-length SLCCNV.The full-length DNA-A was 2730 bp(OM692270.1),and the full-length DNA-B was 2711 bp(OM692269.1).Through sequence alignment,it was found that the DNA-A sequence shared identity of 89.65%-99.42%with registered SLCCNV,and the identity with the SLCCNV-GDHY pumpkin isolate(MW389919.1)in Guangdong was the highest,at 99.42%.The DNA-B sequence was identical with registered SLCCNV in the range of 81.82%-97.29%,and the identity with the SLCCNV-GDHY pumpkin isolate(MW389918.1)in Guangdong,was the highest,at 97.29%.Therefore,it was speculated that SLCCNV is the pathogen of zucchini virus disease.Since the virus was first found on zucchini in Shandong,it was named SLCCNV-SD.[Conclusions]This study provides materials for the research on the spread of SLCCNV in China and the analysis of population genetic characteristics,as well as a reference for the prevention and control of the virus in zucchini.

Squash Hall Indoor Temperature Monitoring System Based on LabVIEW Design

By Using ADAM4000 series data acquisition module, squash hall monitoring system was developed based on the LabVIEW platform. The system consists of master control, signal channel, file operations, digital filtering, spectral analysis, statistic analysis, system monitoring and other modules. The system will alarm at the real time when the result of the average temperature of the squash hall divided by ten is no less than the monitor threshold of 4.3 while athletes are playing squash, by which the temperature and pressure data acquisition, processing and monitoring could be achieved. Application shows that the changes of human exposure temperature between 20°C and 43°C can achieve the comfort level of athletes’ movement, proving that the monitoring system effectively improves the security of squash hall indoor temperature environment.

Influence of cutting size and packaging materials on the quality of fresh-cut winter squash (var. Ajijimang)

Winter squash (var. Ajijimang) washed in 100 mg.L-1 chlorine water and cut into 4 and 8 parts was packed in different packaging materials, 35 μm micro-perforated P-Plus (MPP), 50 μm polyethylene (PE), 80 μm nylon/PE (Ny/PE), and 90 μm PE films separately. Fresh-cut samples were then stored at 10℃ for up to 17 days. The 35 μm MPP having a high oxygen transmission rate (OTR) has the most stable gas exchange ratio while the 80 μm Ny/PE was the most unstable. Firmness of the mesocarp remained acceptable until the end of storage regardless of the cutting size. Soluble solids content (SSC) remained stable and even slightly increased to a certain extent within 6 days. An increase in pH after 10-day storage suggested the activity of microorganisms within the packaging films. Strong off-odor was detected in samples packaged in 80 μm Ny/PE film after 13 days of storage. Mold was observed in all 1/4 cut samples on day 13 except the sample packaged with 80 μm Ny/PE film. However, no mold was found in all 1/8 cut samples except 35 μm MPP film on day 13. Severe mold invasion was apparent on the onset of the 17-day storage in 35 μm MPP film and 50 μm PE film. Samples cut into 8 parts and packed in 80 μm Ny/PE and 90 μm PE films had less mold incidence compared with other two packaging films. Fresh-cut winter squash packaged in 90 μm PE film maintained quality with shelf-life of 10 days at 10℃. Winter squash as fresh-cut commodity, with the right packaging material has the potential for longer period of storage in retail stores.

Technique for Using Spent Mushroom Substrate of Flammulina velutipes to Cultivate Volvariella volvacea in Idle Period of Greenhouse Summer Squash

Greenhouse summer squash is a major type of greenhouse vegetable in Shandong Province.In summer,there is a three-month idle period of greenhouse summer squash.Volvariella volvacea is a high temperature resistant high-quality edible fungus.In practice,it is able to use the spent mushroom substrate of Flammulina velutipes to cultivate V.volvacea.In the idle period of greenhouse summer squash,cultivating V.volvacea using the spent mushroom substrate of F.velutipes has high economic and environmental benefits.The cultivation techniques mainly include the preparation of cultivation materials,preliminary preparation for the greenhouse,planting management of V.volvacea,and returning the spent mushroom substrate to the field.By comparison with the conventional summer squash planting,this technique has higher economic benefits and its application prospects will be broad.

Fruit Yield and Quality, and Irrigation Water Use Efficiency of Summer Squash Drip-Irrigated with Different Irrigation Quantities in a Semi-Arid Agricultural Area

Fruit yield, yield components, fruit mineral content, total p henolic content, antioxidant activity and irrigation water use efficiency(IWUE) of summer squash responses to different irrigation quantities were evaluated with a field study. Irrigations were done when the total evaporated water from a Class A pan was about 30 mm. Different irrigation quantities were adjusted using three different plant-pan coefficients(Kcp, 100%(Kcp1), 85%(Kcp2) and 70%(Kcp3)). Results indicated that lower irrigation quantities provided statistically lower yield and yield components. The highest seasonal fruit yield(80.0 t ha-1) was determined in the Kcp1 treatment, which applied the highest volume of irrigation water(452.9 mm). The highest early fruit yield, average fruit weight and fruit diameter, length and number per plant were also determined in the Kcp1 treatment, with values of 7.25 t ha-1, 264.1 g, 5.49 cm, 19.95 cm and 10.92, respectively. Although the IWUE value was the highest in the Kcp1 treatment(176.6 kg ha-1 mm-1), it was statistically similar to the value for Kcp3 treatment(157.1 kg ha-1 mm-1). Total phenolic content and antioxidant activity of fruits was higher in the Kcp1(44.27 μg gallic acid equivalents(GAE) mg-1 fresh sample) and in the Kcp2(84.75%) treatments, respectively. Major(Na, N, P, K, Ca, Mg and S) and trace(Fe, Cu, Mn, Zn and B) mineral contents of squash fruits were the highest in the Kcp2 treatment, with the exception of P, Ca and Cu. Mineral contents and total phenolic content were significantly affected by irrigation quantities, but antioxidant activity was not affected. It can be concluded that the Kcp1 treatment was the most suitable for achieving higher yield and IWUE. However, the Kcp2 treatment will be the most suitable due to the high fruit quality and relatively high yield in water shortage conditions.

Effects of butternut squash extract on dentate gyrus cell proliferation and spatial learning in male adult rats

Previous studies reported that some plants,including butternut squash,exert positive effects on the brain.However,few studies have examined the effects of butternut squash on learning,memory,and neurogenesis.This study studied the effects of butternut squash extract on spatial learning and cell proliferation in the dentate gyrus of healthy male rats.Thirty-five male Wistar rats were intrap-eritoneally injected with 0,50,100,200 and 400 mg/kg butternut squash extract once daily for 2 months.After the last administration,rat's spatial memory was studied using the Morris water maze.Finally,rats were sacrificed and hippocampal sections were prepared for light microscopy and bromodeoxyuridine immunohistochemistry studies.The results revealed that escape latency and swim distance decreased in all treatment groups compared with the control rats,and that the number of bromodeoxyuridine-positive cells in the dentate gyrus was significantly increased in the treatment groups compared with the controls.These findings suggest that butternut squash extract improves the learning and memory abilities of male rats,and increases the proliferation of dentate gyrus cells.

Dirac Particles' Tunneling Radiation from Dilaton Space-time with Squashed Horizons

The aim of this paper is to investigate Hawking radiation of Dirac particles from the Dilaton space-time with squashed horizons by improving the method of Kerner and Man’s tunneling analysis.We construct appropriate matrices for general covariant Dirac equation,and derive the tunneling probability and Hawking temperature.The results show that both Dirac particles and scalar particles radiate at the same Hawking temperature.

Fermion tunneling from squashed black holes in the Gdel universe and charged Kaluza Klein space time

This paper is devoted to the investigation the fermion tunneling radiation of squashed black holes in the Go¨del universe and charged Kaluza-Klein space-time.For black holes with different dimensions,establishing a set of appropriate matrices γμ for the general covariant Dirac equation plays an important role in the semi-classical tunneling method.By constructing two sets of γμ matrices,we have successfully derived the tunneling probability and Hawking temperature of the black holes.

A Study of Oxalate-Induced Systemic Resistance of Muskmelon to Squash Mosaic Virus

By treatment with oxalate muskmelon cultivar “Wangwenxiang”, which is sensitive to squash mosaic virus (SqMV), develops systemic resistance to SqMV significantly. The challenge inoculation experiments indicate that the symptom of oxalate treated plants gets much slighter, the virus content is only 4% reduced to. The peroxidase activity increases by five times, three new isoperoxidases are induced, and lignin content increases by 82.9%. These results indicate that oxalate induces systemic resistance of muskmelon to SqMV while it induces increase of peroxidase activity, new isoperoxidases and content of lignin in the plants treated with oxalate.

西葫芦新品种京葫42的选育

京葫42是以抗病自交系865为母本,以820为父本配制而成的温室专用抗病西葫芦一代杂种。中早熟,生长势强,茎秆粗壮,低温弱光下连续结瓜能力强,抗白粉病、小西葫芦花叶病毒(ZYMV)、西瓜花叶病毒(WMV)和番木瓜花叶病毒(PRSV);商品瓜翠绿色,中长柱形,瓜条顺直,商品性好;每667 m^(2)产量12000 kg左右,适宜华北、西北、黄淮海和东北地区越冬温室栽培。

Chinese squash leaf curl virus: a new whitefly-transmitted geminivirus

Coat protein (CP) gene of the Chinese squash !eaf curl virus (SqLCV-C) was amplified through PC’R, cloned and completely sequenced. Based on the comparisons at the levels of both CP gene nucleotide and CP -deduced amino acid sequences with other geminiviruses, SqLCV-C is confirmed to be distinct from the American squash leaf curl virus (SqLCV-E). It is a new geminivirus transmitted by whitefly Bemisia tabaci, which infects dicotyledonous plants and is more closely related to the Indian cassava mosaic virus (ICMV).

含连续不均匀椭圆缺陷管道的屈曲失稳分析

为研究外压作用下轴向连续不均匀残余缺陷对海底管道屈曲承载能力的影响,本文基于数值仿真方法研究了轴向含均匀、单峰以及双峰椭圆缺陷管道的屈曲失稳行为,利用弧长法求解管道的屈曲压力,并与DNV-OS-F101规范计算结果进行对比,研究验证了DNV规范预测轴向含非均匀椭圆缺陷管道屈曲压力的保守性,分析了轴向含连续不均匀椭圆缺陷管道屈曲失稳的激发位置及影响参数。研究结果表明:轴向含连续不均匀椭圆缺陷管道的屈曲压力主要由均匀椭圆度以及最大局部椭圆度决定,各缺陷间距范围内屈曲压力变化规律各不相同,且上升下降幅度受椭圆缺陷间距与最大椭圆度间耦合作用影响。