贝莱斯芽孢杆菌对采后葡萄果实贮藏品质的影响

通过研究贝莱斯芽孢杆菌对葡萄果实贮藏品质的影响,为提高葡萄果实采后贮藏稳定性,延长贮藏期提供科学依据。以“玫瑰香”葡萄为试材,用拮抗菌溶液（TP-1）处理葡萄果实,以无菌水处理作为对照,处理后将果实分别置于25 ℃与4 ℃条件下贮藏,测定葡萄果实贮藏期间腐烂率、失重率、可溶性固形物含量、相对电导率、硬度、果皮色度、VC含量以及可滴定酸含量的变化。结果表明：整个贮藏期间,贝莱斯芽孢杆菌TP-1处理可以有效降低葡萄果实腐烂率,常温贮藏25 d时,腐烂率仅为42%,低于其他处理组;葡萄果实失重率在贮藏期内大幅上升,但贝莱斯芽孢杆菌TP-1处理果实失重率均低于对照组,在常温贮藏25 d时,效果最明显;葡萄果实硬度在贮藏期内逐渐下降,常温贮藏15~25 d果实硬度下降最快,贮藏25 d时,贝莱斯芽孢杆菌TP-1处理组果实硬度最高,为1.21 kg/cm2。此外,贝莱斯芽孢杆菌TP-1处理还可抑制葡萄果实相对电导率的上升,维持果皮色度和较高水平的可溶性固形物含量,延缓可滴定酸和VC降解。贝莱斯芽孢杆菌TP-1处理组能有效维持葡萄果实贮藏品质。     

“仙果”哈密瓜晒瓜处理后贮藏及生理特性的研究

以沪产"仙果"哈密瓜为试材,进行采前晒瓜处理,研究在温度3,5,8℃和常温贮藏条件下,哈密瓜采后贮藏期间果实生理代谢的变化。结果表明,晒瓜处理后低温贮藏,能有效地降低哈密瓜果实的腐烂,抑制了总酸、总糖、可溶性固形物含量和果实硬度的下降,显著延长哈密瓜的贮藏时间。以糖、酸含量和果实硬度、腐烂率为评价指标,确定5℃为"仙果"的适宜贮藏温度。     

不同贮藏条件对草莓贮藏品质的影响

为提高草莓的贮藏品质,寻求适合草莓的贮藏条件,将新鲜草莓分别置于常温阴凉（20 ℃）、冷藏库（0 ℃和-3 ℃）条件下贮藏7 d,每天测定草莓的可溶性固形物、可滴定酸、VC含量,同时监测失重率、腐烂指数和感官品质,研究不同贮藏条件对草莓品质的影响。结果表明：贮藏期间,冷藏库0 ℃贮藏草莓的可滴定酸和VC含量高于冷库-3 ℃和常温20 ℃贮藏的草莓,0 ℃贮藏7 d的草莓可滴定酸和VC含量分别为0.58%、29.8 mg/100 g;贮藏7 d时,-3 ℃贮藏草莓的可溶性固形物含量高于0 ℃和20 ℃处理,失重率和腐烂指数最低,分别为8.41%、8%、9.93;贮藏期间,0 ℃和-3 ℃贮藏草莓的感官品质均较好,优于20 ℃贮藏的草莓。综上可得,冷藏库0 ℃和-3 ℃贮藏草莓的品质优于常温20 ℃贮藏的草莓;冷藏库-3~0 ℃低温贮藏有利于保持草莓的品质,且避免草莓冻害。该研究可为草莓贮藏保鲜技术的研发提供参考。     

热空气处理对‘白玉’枇杷品质及冷害的影响

为研究热空气处理对“白玉”枇杷贮藏品质及冷害的影响,本文以“白玉”枇杷为试材,探索了46℃热空气处理对蛋白组分含量变化的影响,并对各处理（6±1）℃冷藏期间果实冷害指数、可溶性固形物、可滴定酸、失重率、腐烂率和果实硬度进行测定。试验结果表明：冷藏及货架期间,46℃热空气处理果实可维持较高的可溶性蛋白和热稳定蛋白含量;抑制了冷藏期间果实可溶性固形物、可滴定酸含量的下降,保持了较高的果实硬度,显著降低了果实的腐烂率、失重率和冷害指数,其中以46℃热空气处理30min后冷藏效果最好。以上结果显示,果实蛋白组分含量的变化与果实采后冷藏过程中抗冷性有关,且热空气处理提高了果实的贮藏品质。     

低温对贵妃枇杷采后果实品质的影响

研究了低温条件对贵妃枇杷采后品质的影响。结果表明,低温能显著抑制果实的失重,延缓糖、酸含量的下降;前期果实硬度下降,后期上升;采后各处理的可食率、可溶性固形物含量下降;贵妃枇杷的适宜贮藏温度为6-8℃ ,贮藏20-30d仍能保持较好的品质。     

不同品种及采收时期番茄果实的品质分析

以丰收560、京采8号、Cap、Saopolo和Jua 5个番茄品种为研究对象,设置了5个采收时期,通过测定可溶性固形物、可滴定酸、可溶性糖含量等品质指标,分析不同品种番茄及采收时期的品质差异性,以期为番茄品质分级提供依据。结果表明:不同番茄品种的品质存在明显差异性,其中Saopolo的可溶性固形物、可溶性糖、可滴定酸、VC含量平均值最高,分别为8.92%、7.35%、0.66%和4.57 mg/g,均显著高于除Jua外的其他品种;丰收560的可溶性固形物、可溶性糖含量平均值最低,分别为3.64%、2.04%;不同采收时期的番茄果实品质存在一定差异性,其中可溶性固形物含量、固酸比、VC含量和a*值等果实品质均存在显著差异,可溶性糖含量、可滴定酸含量、糖酸比、L*值、硬度和感官品质等差异较小。综上,在番茄品质分级时,可将可溶性糖含量、可滴定酸含量、糖酸比、L*值、硬度和感官品质作为分级指标,以减少采收时期对品质分级的影响。     

不同货架温度对冰温贮藏红富士苹果品质的影响

红富士苹果冰温、0℃下贮藏5个月、7个月后分别移入不同温度货架,对果实感官及营养品质进行比较研究。结果表明,与0℃贮藏相比,5个月、7个月冷藏及货架期,冰温贮藏保持了红富士苹果较好的贮藏期及货架期品质。5℃货架温度较15℃下果实失重、硬度、可溶性固形物含量、可滴定酸含量下降缓慢,果面h值增加及果肉L*值下降减缓,花色苷、类黄酮、总酚含量损失率低。果实的营养品质较感官品质在较高的货架温度下损失率更高。因此,适宜的低温贮藏及货架温度可有效保持果实的感官及营养品质。     

臭氧处理对哈密瓜常温贮藏品质的影响

以"西州蜜25号"哈密瓜为原料,在常温下分别对其进行0 mg/m³(对照组)和10 mg/m³臭氧(处理组)处理4 h,并置于常温(22±2)℃下进行贮藏。通过观察哈密瓜果实的腐烂症状,测定腐烂指数、可溶性糖等指标,研究10 mg/m³臭氧处理对哈密瓜贮藏品质的影响。结果表明:与对照组相比,臭氧处理可降低果实腐烂指数,减轻腐烂症状,抑制果实呼吸作用,并延缓果实硬度和抗坏血酸含量的下降速度,较好地维持了果实可溶性固形物、可滴定酸、可溶性糖和可溶性蛋白含量,一定程度上保持了果实的贮藏品质。     

不同贮藏温度对蓝莓果实贮藏特性的影响

为研究不同温度下不同品种蓝莓果实的贮藏特性,以天津蓟州区主栽的8个蓝莓品种为试材,分别在10、4、0、-1℃贮藏条件下比较了果实的5个贮藏特性动态变化。结果表明,在4种贮藏温度下,温度越低,蓝莓果实好果率越高,失重率越低,硬度及可溶性糖含量的下降率越低,可溶性固形物含量保持越好。在10℃贮藏过程中,随着贮藏时间的延长,好果率逐渐降低,失重率逐渐增加,贮藏至14 d时,蓝莓的好果率在23.33%～85.33%,失重率在13.37%～27.40%;4℃贮藏过程中,好果率随时间延长逐渐降低,而失重率逐渐增加,贮藏至至21 d时,好果率在19.67%～69.50%,失重率在21.74%～35.66%;0℃和-1℃条件下,可溶性固形物含量均呈现先上升后下降的趋势,贮藏至70 d时,好果率在57.60%～95.67%,失重率在4.98%～17.72%,硬度较初值下降了20.69%～57.67%,可溶性固形物含量较初值下降了1.82%～61.71%,可溶性糖含量较初值下降了14.12%～42.17%。隶属函数综合分析不同贮藏温度条件下耐贮藏品种为布里吉塔、蓝金、莱克西。综合比较各指标发现,不同品种蓝莓在-1～0℃下贮藏均可维持较好的果实商品性(好果率和失重率)和果实品质(硬度、可溶性固形物及可溶性糖含量)。     

柠檬酸对鸭梨贮藏后期微生物数量和品质的影响

为探讨柠檬酸对鸭梨贮藏后期的保鲜机制,以鸭梨为试材,采用不同浓度的柠檬酸溶液浸泡鸭梨果实,在4℃的条件下分别贮藏10天、20天、30天,测量了贮藏后期柠檬酸处理对鸭梨的硬度、可溶性糖、可溶性固形物以及霉菌和酵母菌的数量的变化的影响。结果表明:在试验期间,4种浓度柠檬酸浸泡处理均可在不同程度上降低果实的失重率和腐烂率,其中2%柠檬酸浸泡处理的鸭梨贮藏的效果最佳,其腐烂率和失重率分别为8.3%和18.18%,抑制了果实贮藏后期微生物数量,防止硬度、可溶性糖以及可溶性固形物含量的下降。柠檬酸处理是鸭梨贮藏后期为改善鸭梨品质和控制微生物数量的一种可选方法。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Breeding forage grasses for organic conditions

Herbage yield trials are necessary to test if candidate varieties are well suited for organic conditions. In order to elucidate a particular suitability for organic conditions, we run such trials in parallel under both organic and conventional conditions. Here, we report on second and third year results of the sowings 2004 and 2005. These trials are part of a targeted breeding programme for organic conditions. Irregular colonisation of pure grass plots with adventitious plants, in particular white clover, was recognized as a major constraint to the quality of the results obtained under organic conditions. The coefficients of variance in dry matter yield almost doubled when compared to conventional trials, and significant differences in annual yield among varieties were rare. However, when herbage yield was corrected for the estimated fraction of adventitious plant colonization at each cut, the number of instances with statistically significant differences for annual yield among varieties increased more than fourfold. Dry matter yields under organic and conventional conditions were significantly and positively correlated. However, analysis of variance showed a significant culture type by variety interaction for annual dry matter yield in 12 out of 24 trials. When diploid and tetraploid varieties of the same Lolium species were tested in one common trial, only tetraploid varieties were identified as being particularly well suited for organic conditions, while in these trials, the great majority of apparently poorly suited varieties were diploid. This suggests that breeding tetraploid Lolium varieties is promising when aiming at a favourable response to organic agriculture.     

The performance of double or mixed pollinations with compatible and self-incompatible or incongruous pollen of pear and apple

Summary Six pear and five apple trials were carried out to ascertain the outcome of combinations of compatible pollen (C) with self (S) or incongruous pollen (I) as to the pollination index (PI=seeds/pollinated flower). The PI of the mixture C+I (1:5) was consistently depressed as compared to that of the control C. The results of the double pollinations S/C and I/C were affected by the temperature at pollination; their PI's at <15°C were twice as high as those at >15°C, being well above and below the PI of C in the former and latter case respectively. The opposite was true for the C/S combination, the PI of which increased with the pollination temperature; the PI of C/I did not differ much from the PI of C, irrespective of temperature. The conclusion was reached that the interaction previously and presently found between compatible and self-incompatible pollen also exists to a fair extent between compatible and incongruous pollen. However, in pear neither the mentor nor the pioneer pollen technique proved to aid its hybridization with apple, the formation of self seed was not observed either. In apple the production of apple × pear hybrids was likewise doubtful, but the double pollinations S/C and C/S formed 4–10% self seed.