Germination and net in vitro growth of peach, almond and peach-almond hybrid embryos in response to mannitol inclusion in the nutrient medium

Nine Prunus accessions were evaluated for germination and plantlet growth in an in vitro osmotic screening test using mannitol as an osmoticum. Embryos from diverse peaches, almonds and peach-almond hybrids were cultured in Woody Plant Medium, and in this same medium modified with the inclusion of 350 mM mannitol. Embryos were stratified in vitro for 60 days, induced to germinate for a two week period and then allowed to develop and grow for another 20 days prior to harvest. Fresh weights of both roots and shoots as well as percent germination were recorded at harvest. The main effects of nutrient medium, germplasm type (peach, peach-almond, almond) and specific Prunus accession were all highly significant (P = 0.01) with regard to fresh weight of roots and shoots. Embryo germination was affected significantly by the inclusion of mannitol in the nutrient medium and by the particular germplasm type (P=0.01 and P=0.05, respectively). Significant interactions of nutrient medium × Prunus accession and nutrient medium × germplasm type were also detected for both root and shoot fresh weights. Almond germplasm cultured in Woody Plant Medium with 350 mM mannitol produced significantly more roots and shoots than either peaches or peach-almond hybrids grown in the same medium. Peach-almond hybrid embryos were observed to germinate at a significantly higher frequency than peach embryos when averaged across both media. Results obtained in this study indicate a wide range of average plantlet fresh weight relative to the specific germplasm challenged in the osmotic screen. This revised version was published online in August 2006 with corrections to the Cover Date.     

棉花植株和花粉耐盐性的鉴定

本研究对８个耐盐性不同的棉花品种（系），利用水培的方法对其整体植株进行了耐盐性鉴定，利用液滴培养技术对其花粉的耐盐性进行了鉴定，并分析了棉花整体植株和花粉耐盐性的相关性，结果表明，在水培盐胁迫条件下，棉花叶片总面积和叶片鲜重减少的百分数是反映棉花整体植株耐盐性的指标。在液滴培养盐胁迫条件下，棉花花粉粒萌发的百分率是反映其耐盐性的可靠指标，而花粉管的长度不能反映棉花的耐盐性。棉花整体植株的耐盐性和花     

Rapid Screening for Aluminum Tolerance in Cereals by Use of the Chlorophyll Fluorescence Test

The effects of aluminum on the photosynthetic apparatus were examined in cereals grown in nutrient solutions (pH 4.5) at two Al levels (0 and 148 μM). The chlorophyll fluorescence kinetics results confirmed that the soft wheat ‘BHG’ cultivar has the potential for growth on acid soils while triticale cultivars ‘Niovi’ and ‘Dada’ appeared to be relatively tolerant. The percentage decrease in F_v/F_m of the less tolerant cultivars after Al-treatment indicated a decrease in the efficiency of the primary photochemistry of PS II, while the decrease in the ratio F_V/F_osuggested that exposure of the cultivars ‘Dio’ and ‘Appulo E’ to aluminum caused injury to the thylakoid structure. The percentage fluctuations of the ratio F_v/F_mwere shown to correlate very closely with the assessment of injury as evaluated by the relative top fresh weight. Measurements of chlorophyll fluorescence in vivo could be used to monitor injury caused by “Al-stress”, and thus they may serve as a rapid screening test for Al tolerance.     

Evaluation of a collection of faba bean (Vicia faba L.) genotypes originating from the Maghreb for resistance to chocolate spot (Botrytis fabae) by assessment in the field and laboratory

Screening of 136 faba bean lines forresistance to chocolate spot caused by thefungus Botrytis fabae was conductedin field conditions with artificialinoculation. Detached leaves of thesegenotypes were also assessed for diseaseseverity after inoculation under controlledconditions with a B. fabaesuspension. The BPL710 and Aguadulcegenotypes were inserted as resistant andsusceptible checks, respectively. Diseasesymptoms were scored visually in bothexperiments. Diameter of lesions andproduction of spores were measured in thedetached leaf assay. The disease scoreindex and diameter of lesions were used tocalculate the area under the diseaseprogress curve (AUDPC) to measure thedisease progress. Significant differenceswere detected among genotypes for reactionto the disease in the field. However, nocomplete resistance was observed. Forhighly susceptible and highly resistantgenotypes, the laboratory assay generallyled to the same result as the field test,nevertheless, for more intermediate levelsthe agreement was weak. On detached leaves,diameter of lesions was significantlycorrelated to the AUDPC of disease scores(r = 0.89) and moderately correlated tosporulation (r = 0.52). The correlationbetween field AUDPC and detached leaf AUDPCof disease scores was low (r = 0.26). A lowcorrelation was also observed between fieldAUDPC and lesion size (r = 0.30) andbetween field AUDPC and sporulation (r =0.32). Among the 136 genotypes evaluated inthis study, nine were convincingly andhighly resistant in both tests. FRYM167 andFRYA58 genotypes were the most resistantwith low AUDPC of disease scores, low AUDPCof lesion diameter and low sporeproduction. These genotypes obviously havepartial resistance.     

海棠果实功能性成分与高含量资源筛选

海棠果富含糖酸、维生素、单宁等多种功能性成分,在功能食品的开发方面具有广阔的应用前景。本研究选取了48个杂交海棠株系的果实,对其果实主要的外观性状和功能性成分：可溶性总糖、可滴定酸、维生素C和单宁含量进行测定。根据其综合性状的表现,分别筛选出功能性成分含量较高、外观品质较好的优系。结果表明：海棠果实内功能性成分含量均显著高于苹果内的含量,其中海棠内可溶性总糖、可滴定酸、维生素和单宁含量最高可分别达到苹果的1.86、2.23、6.72、33.4倍。所筛选出的海棠优系不仅可以作为与苹果杂交的亲本,改善苹果的营养和口味,同时还对育种工作者培育综合农艺性状的优良品种、拓宽海棠种质资源具有一定的参考价值。     

Recurrent breeding method enhances the level of blackspot (Didymella pinodes (Berk. & Blox.) Vestergr.) resistance in field pea (Pisum sativum L.) in southern Australia

Blackspot, caused by Didymella pinodes (Berk. & Blox.)Vestergr., is one of the most important diseases of field pea, causing significant reduction in seed yield and quality in southern Australia and in other parts of the world. Development of resistant germplasm has been slow because of the low level of resistance found in the available germplasm, poor reliability of screening methods and the polygenic nature of inheritance. Crosses were made between agronomically suitable lines and resistant germplasm from different sources. Their progeny were advanced through the single seed descent method and single plants were selected at F₄/F₅. The F₄/F₅ derived lines were screened against blackspot in the field under disease pressure and evaluated for grain yield at multilocations over 2 years. Despite the low level of resistance in the parental germplasm, the level of resistance has increased significantly in the new germplasm. Many of the resistant lines were late and low yielding, but lines with higher resistance and early flowering and high yield potential were also identified indicating that the disease resistance, adaptation and yield potential can be combined. However, the resistance identified in this study is only partial and suitable agronomic practices may need to be supplemented to minimise the yield loss and enhance the benefits of this partial resistance.     

Barley mutants with increased tolerance to aluminium toxicity

Acid soil and associated aluminium toxicity are considered as the number one abiotic factor limiting crop production. Over 2 billion hectares of acid soils exist world-wide, both in tropical and moderate climatic zones. In Poland acid soils represent up to60% of arable land. At soil pH < 5.0 Al ions become soluble in water and toxic to plants. Genetic improvement of Al tolerance in crops is the only alternative to soil liming, a traditional but short term and expensive agricultural cure to raise soil pH. Of the various cereals, barley is the most sensitive to Al toxicity. The known sources of Al tolerance in barley are limited to old cultivars and landraces. While they represent multiple alleles of a single locus, there is no potential to improve Al tolerance through recombination of non-allelic additive genes. In the Department of Genetics, Silesian University we have employed induced mutations for rapid creation of variability for Al tolerance in barley. Thirteen mutants with increased levels of tolerance to Al toxicity have been selected in M₃ generation after mutagenic treatment of four barley varieties with N-methyl-N-nitroso urea (MNH) and sodium azide. Six further Al tolerant mutants were identified in the collection of semi-dwarf mutants of the Department. All selected mutants confirmed Al tolerance with the use of three different methods of screening, i.e., root re-growth, root tolerance index and hematoxylin staining. Fourteen mutants exhibited significant root re-growth after 48 hour incubation with 3 ppm Al⁺³ and two of them, namely RL819/2 and RL820/6 were tolerant even to 6 ppm Al⁺³. Crosses of two selected mutants with their respective parent varieties indicated that Al tolerance in each mutant was controlled by a single recessive gene. Out of three methods tested, the root re-growth method facilitated by hematoxylin staining proved to be the most reliable technique for large scale testing. Double treatment with MNH or combined treatment with sodium azide and MNH and 6hinter-incubation germination between treatments were the most successful treatment combinations for induction of aluminium tolerance in barley. This revised version was published online in August 2006 with corrections to the Cover Date.     

生物农药防治棚室秋番茄病毒病效果探讨

为减轻番茄病毒病发生危害,减少化学农药用量、残留和环境污染,采用测报调查、随机区组设计和统计分析等方法,开展了生物农药香菇多糖 赤.吲乙.芸苔和宁南霉素 赤.吲乙.芸苔防治番茄病毒病农药田间药效试验。结果表明,在温室大棚秋季番茄病毒病发生较重情况下,每hm2用0.5%香菇多糖AS 3000mL 碧护WP 600g、8%宁南霉素AS 900mL 碧护WP 600g,7天施药1次,连续施用4次,药后10天、17天、26天和35天,防治效果均在88%、87%、78%和67%以上,且两药剂防治效果差异不显著,香菇多糖 赤.吲乙.芸苔极显著高于盐酸吗啉胍(对照药剂) 赤.吲乙.芸苔,宁南霉素 赤.吲乙.芸苔显著高于盐酸吗啉胍 赤.吲乙.芸苔。香菇多糖 赤.吲乙.芸苔和宁南霉素 赤.吲乙.芸苔不仅可以作为防治病毒病的理想药剂,而且可以作为现代农业示范区、无公害农产品、绿色农产品和有机农产品防治病毒病的理想药剂。     

金银花中戊唑醇、苯醚甲环唑的残留分析

为解决金银花种植过程中农药的使用问题,以金银花为试验对象,选用广谱杀菌剂戊唑醇和苯醚甲环唑,采用常量、倍量、二次和三次灌根处理,对最终的残留含量进行分析。头茬花各处理中苯醚甲环唑均未检出,而二茬花中戊唑醇的残留量为0.14~0.22 mg/kg,存在残留超标风险。建议使用10%苯醚甲环唑4000倍液灌根处理,防治金银花土传病害,灌根2~3次,安全间隔期15天。     

荞麦轮纹病抗性鉴定方法的建立及荞麦抗病种质资源的筛选

为建立荞麦轮纹病的抗性鉴定方法和筛选可利用的抗轮纹病的荞麦种质资源,本研究以TP2和KP14为供试材料,在健康荞麦叶片正面针刺处理,然后用荞麦轮纹病的病原菌菌饼进行接种;利用建立的抗性鉴定方法,对50份荞麦种质资源进行抗病性评价。结果显示:针刺5针接种叶片病斑出现较快,且比针刺1针、针刺3针的叶片病斑大,针刺5针的病情指数最高。50份荞麦种质资源的病情指数有差异,其中YZ-18的病情指数为29.63,为高抗种质资源,YZ-2、YZ-5、YZ-13和YZ-9的病情指数均低于40,为中抗种质资源,其余为感病种质资源。因此,接种前叶片正面针刺5针的方法为最佳的抗性鉴定方法。50份抗性评价的荞麦种质资源中,筛选出5份抗病种质资源。