咯菌腈与二氧化氯复合杀菌对甜樱桃的贮藏效果

研究了在0±1℃温度下,采用MAP膜袋包装,复合咯菌腈与二氧化氯处理对甜樱桃品种拉宾斯品质的影响。结果表明,在贮藏60天内,20mg/kgClO_2+200mg/kg咯菌腈处理比单用20mg/kgClO_2能有效控制甜樱桃果实贮藏期间的腐烂;果实硬度变化不大,可溶性固形物含量、可滴定酸含量下降速度变缓;但果实的亮度和色度下降更快。     

氰霜唑和咯菌腈在番茄上降解规律研究

采用液相色谱法,研究了氰霜唑和咯菌腈在番茄的降解规律。结果表明氰霜唑在番茄上的平均回收率为84.42%~96.44,变异系数为5.78%~6.82%;咯菌腈在番茄上的平均回收率为81.85%~92.43%,变异系数为3.68%~7.90%。符合农药残留检测要求。氰霜唑和咯菌腈在番茄上施药7天后,其残留量分别为0.39mg/kg和0.26mg/kg,小于欧盟最新食品农药残留限量标准0.5mg/kg。     

外施GA3对台农17号菠萝果实品质及内源激素的影响

为探究采前外施不同浓度GA₃对台农17号菠萝采后果实品质及内源激素含量变化的影响，共设置4个GA₃浓度处理，分别为50、100、150、200 mg/kg，以清水处理为对照(CK)。结果表明：150、200 mg/kg GA₃处理可增大果实体积、提高果实重量，100、150 mg/kg GA₃处理可增加果实甜度，其中100 mg/kg GA₃处理果实总糖含量最高；而150、200 mg/kg GA₃处理可降低果实可滴定酸含量、增大果实p H值，同时高浓度GA₃可提高果实糖酸比，从而影响果实的口感与风味；100 mg/kg GA₃处理还可提高果实维生素C含量，当GA₃处理浓度高于100mg/kg时反而降低了果实维生素C含量。此外，不同浓度GA₃处理对果实内源激素含量的影响较大，经GA₃处理后可增加果实内源GA₃含量，也可提高果实...     

高效氯氟氰菊酯在杨梅果实中的残留研究

为研究高效氯氟氰菊酯在杨梅果实上使用后的残留降解情况,2014—2015年连续2年,分别以‘东魁’‘临海早大梅’杨梅为试材,在杨梅春梢(幼果)生长期树冠喷施5%高效氯氟氰菊酯微乳剂1 000倍液,分析其在杨梅果实中的残留消解动态和最终残留量。结果表明:高效氯氟氰菊酯在‘东魁’‘临海早大梅’果实中半衰期分别为6.5、8.2 d,前期降解较快,后期降解慢;喷药后20 d果实中的残留量分别为0.081、0.100 mg/kg,达到我国浆果和其他小粒水果中最大残留量标准;至采收期,即喷药34 d后,果实中高效氯氟氰菊酯残留量分别为0.034、0.068 mg/kg,远低于国标0.2 mg/kg的限量标准。建议5%高效氯氟氰菊酯在杨梅生产中施用浓度不超过1 000倍液,喷施1次,推荐安全间隔期不少于20 d,出口杨梅在挂果期不要使用。     

不同药剂组合对西瓜促长防病效果试验

本试验研究了在西瓜植株生长前期用3种浓度的62.5 g/L精甲·咯菌腈SC加益施帮氨基酸水溶肥灌根,并结合32.5%苯甲·嘧菌酯SC加20%噻唑锌SC叶面喷雾对西瓜生长的影响及主要病害的防效。试验结果表明,用62.5 g/L精甲·咯菌腈SC 1 000倍液加益施帮氨基酸水溶肥750倍液(每株用量750 mL)灌根,且每隔10 d用32.5%苯甲·嘧菌酯SC 1 500倍液加20%噻唑锌SC 500倍液叶面喷雾,对西瓜叶枯病、根腐病的防效优异,并能促进西瓜生长,提高产量和品质。     

4种杀菌剂对连作苹果园土壤镰刀菌及土壤酶活性的影响

【目的】老果园栽植新树苗时遇到幼苗生长不良等连作问题越来越突出,因此对苹果连作障碍的研究尤为必要。本试验旨在筛选出高效、低毒的化学杀菌剂,通过药剂混土的方式缓解果树连作障碍问题。【方法】通过田间试验,研究了多菌灵、福美双、咯菌腈、代森锰锌连作树穴(连作土)用药量分别为10 g a.i/10 kg土、10 g a.i/10 kg土、2.5 g a.i/10 kg土和10 g a.i/10 kg土,行间树穴(非连作土)用药量分别为5 g a.i/10 kg土、5 g a.i/10 kg土、2.5 g a.i/10 kg土和5 g a.i/10 kg土对苹果连作土壤镰刀菌及土壤酶活性的动态影响。【结果】四种杀菌剂对土壤镰刀菌毒力测定结果表明,咯菌腈对连作土壤串珠镰刀菌的控制效果最好,EC50仅为0.356 mg·L-1。对连作土壤镰刀菌抑制率最高达80.17%,对行间土壤镰刀菌抑制率最高达86.48%;苹果幼树生长测定结果表明:代森锰锌对幼树生长的促进作用最为明显,与其他处理差异显著。连作树穴幼树枝条数、茎粗度、叶片数、新梢长、叶面积分别增加了2条、0.20 cm、10.84枚、27.54 cm、9.84cm2,行间树穴幼树分别增加了1.92条、0.16 cm、14.26枚、22.19 cm、5.55 cm2;对土壤酶活性测定结果表明,不同药剂对不同土壤酶影响不同,咯菌腈对过氧化氢酶激活作用最强,多菌灵对蔗糖酶的激活作用最强,福美双对中性磷酸酶的激活作用最强,多菌灵对脲酶激活作用最强。各土壤酶活性在8月份以后普遍降低,药剂对土壤酶激活作用消失。【结论】杀菌剂可以有效抑制土壤镰刀菌的生长,减轻苹果连作障碍问题。     

聚-γ-谷氨酸提升柠檬产量和品质的研究

本文配合春肥和壮果肥的施用,用不同浓度的聚-γ-谷氨酸(PGA)对尤力克柠檬进行灌根试验,研究了PGA对柠檬产量和品质的影响。结果表明:经过3种不同浓度(50、100和200mg/L)的PGA灌根处理,柠檬果实单果重均比对照有所提高,分别增加了62.2%、79.5%和28.3%。PGA浓度为50、100mg/L时,果实的可滴定酸含量分别比对照提高了4.3%和2.9%;果色比对照更鲜艳,果实横径和纵径均有所增长。PGA浓度为200mg/L时,果实中的还原糖含量比对照的增加12.77%,增幅达到极显著水平;蛋白质含量比对照增加7.51%,差异达到显著水平。     

16种杀菌剂及其复配对番茄晚疫病的室内毒力测定及温室防效

采用生长速率法测定16种杀菌剂单剂药效并筛出对番茄晚疫病增效作用较好的混剂配比。结果表明氰霜唑、咯菌腈、氨基寡糖素、吡唑醚菌酯、烯酰吗啉的EC50值分别为0.21、0.37、0.46、0.65、0.74mg/L,抑菌效果均较好。将氰霜唑分别于其他四种杀菌剂复配,其中咯菌腈和氰霜唑以质量比为1∶1混配时,EC50值为0.08mg/L,增效系数为3.38,增效作用明显。在温室防效试验中,采用常规喷雾法,质量分数为40%咯菌腈·氰霜唑在100g.a.i/hm2剂量下防效最好,达到93.66%,可为农业生产提供有效的科学理论指导。     

“枣丰素”叶面肥对冬枣产量、品质和耐贮性的影响

利用"枣丰素"叶面肥对冬枣产量、品质和耐贮性的影响进行了试验。结果表明:125mg/kg浓度的"枣丰素"对冬枣果实含糖量、产量增加显著,果实在自然条件下货架期最长;喷施100、150mg/kg浓度的"枣丰素"对冬枣果实含糖量、产量增加不显著;在自然条件下货架期与对照比较,喷施100mg/kg浓度的冬枣果实有所延长,喷施150mg/kg浓度的冬枣果实较对照几乎没有延长。     

GA_3处理对夏黑葡萄果穗生长与果实品质的影响

以4年生夏黑葡萄为试材,研究赤霉素(GA_3)不同处理时期与处理浓度对夏黑葡萄果穗生长与果实品质的影响。结果表明,在花前2周,3mg/kg、5mg/kg和10mg/kg GA_3处理对夏黑葡萄不同发育时期花序的生长均无显著影响;应用赤霉素GA_3膨大夏黑葡萄果粒的最适处理方法为,盛花期用20mg/kg浓度GA_3处理1次,在花后12d左右再用25mg/kg浓度GA_3处理1次;在田间劳动力不足条件下,可选择在花后12d左右,用100mg/kg GA_3处理1次,也能达到膨大果粒的目的。     

Plant growth,yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on four rootstocks

Vegetative growth, yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on ‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘Orlando’ tangelo, and ‘Cleopatra’ mandarin were evaluated under subtropical climate of Northern São Paulo State, Brazil, from 2000 through 2006 harvest seasons. ‘Fallglo’ mandarin trees had the highest cumulative yield on ‘Rangpur’ lime, and the smallest on ‘Swingle’ citrumelo and ‘Orlando’ tangelo. Plants of this cultivar had the highest yield efficiency on ‘Rangpur’ lime, and the lowest on ‘Orlando’ tangelo. ‘Sunburst’ mandarin trees began to bear fruits later than ‘Fallglo’ mandarin trees, with no differences in yield induced by the rootstocks. ‘Cleopatra’ mandarin induced the most vigorous growth in ‘Fallglo’ mandarin as compared to plants on ‘Swingle’ citrumelo. On the other hand, the largest trees of ‘Sunburst’ mandarin were registered on ‘Orlando’ tangelo, and the smallest on ‘Rangpur’ lime. ‘Sunburst’ mandarin had higher alternate bearing than ‘Fallglo’ regardless the rootstock. Fruit weight and juice content were not affected by the rootstock. These two mandarin scion cultivars may be considered adequate alternatives to produce good fruit quality for the fresh fruit market. ‘Cleopatra’ mandarin and ‘Rangpur lime are suitable rootstocks for ‘Fallglo’ mandarin, whereas all rootstocks evaluated are adequate for ‘Sunburst’ mandarin.     

Tree performance and fruit yield and quality of ‘Okitsu’ Satsuma mandarin grafted on 12 rootstocks

The citriculture in Brazil, as well as in other important regions in the world, is based on very few mandarin cultivars. This fact leads to a short harvest period and higher prices for off-season fruit. The ‘Okitsu’ Satsuma (Citrus unshiu Marc.) is among the earliest ripening mandarin cultivars, and it is considered to be tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.) and to citrus variegated chlorosis (Xylella fastidiosa Wells et al.). Despite having regular fruit quality under hot climate conditions, the early fruit maturation and absence of seeds of ‘Okitsu’ fruits are well suited for the local market in the summer (December through March), when the availability of citrus fruits for fresh consumption is limited. Yet, only a few studies have been conducted in Brazil on rootstocks for ‘Okitsu’. Consequently, a field trial was carried out in Bebedouro, São Paulo State, to evaluate the horticultural performance of ‘Okitsu’ Satsuma mandarin budded onto 12 rootstocks: the citrandarin ‘Changsha’ mandarin (Citrus reticulata Blanco) × Poncirus trifoliata ‘English Small’; the hybrid Rangpur lime (Citrus limonia Osbeck) × ‘Swingle’ citrumelo (P. trifoliata (L.) Raf. × Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.) ‘Rubidoux’, ‘FCAV’ and ‘Flying Dragon’ (P. trifoliata var. monstrosa); the mandarins ‘Sun Chu Sha Kat’ (C. reticulata Blanco) and ‘Sunki’ (Citrus sunki (Hayata) Hort. ex. Tanaka); the Rangpur limes (C. limonia Osbeck) ‘Cravo Limeira’ and ‘Cravo FCAV’; ‘Carrizo’ citrange (Citrus sinensis × P. trifoliata), ‘Swingle’ citrumelo (P. trifoliata × C. paradisi), and ‘Orlando’ tangelo (C. paradisi × Citrus tangerina cv. ‘Dancy’). The experimental grove was planted in 2001, using a 6 m × 3 m spacing, in a randomized block design. No supplementary irrigation was applied. Fruit yield, canopy volume, and fruit quality were assessed for each rootstock. A cluster multivariate analysis identified three different rootstock pairs with similar effects on plant growth, yield and fruit quality of ‘Okitsu’ mandarin. The ‘Flying Dragon’ trifoliate had a unique effect over the ‘Okitsu’ trees performance, inducing lower canopy volume and higher yield efficiency and fruit quality, and might be suitable for high-density plantings. The ‘Cravo Limeira’ and ‘Cravo FCAV’ Rangpur limes induced early-ripening of fruits, with low fruit quality. ‘Sun Chu Sha Kat’ and ‘Sunki’ mandarins and the ‘Orlando’ tangelo conferred lower yield efficiency and less content of soluble solids for the latter rootstock.     

Evaluation of citrus somatic hybrids for tolerance to Phytophthora nicotianae and citrus tristeza virus

Somatic hybridization is a biotechnology tool that can be used in citrus breeding programs to produce somatic hybrids with the complete genetic combination of both parents. The goal of this work was to test the reaction of citrus somatic hybrids that may be useful as rootstocks to trunk and root infections caused by Phytophthora nicotianae van Breda de Haan (P. parasitica Dastur) and to citrus tristeza virus (CTV). The somatic hybrids evaluated were ‘Caipira’ sweet orange (Citrus sinensis L. Osbeck) + ‘Rangpur’ lime (C. limonia Osbeck), ‘Caipira’ sweet orange + ‘Cleopatra’ mandarin (C. reshni hort. ex Tanaka), ‘Caipira’ sweet orange + ‘Volkamer’ lemon (C. volkameriana V. Ten. & Pasq.), ‘Caipira’ sweet orange + rough lemon (C. jambhiri Lush.), ‘Cleopatra’ mandarin + ‘Volkamer’ lemon, ‘Cleopatra’ mandarin + sour orange (C. aurantium L.), ‘Rangpur’ lime + ‘Sunki’ mandarin (C. sunki (Hayata) hort. ex Tanaka), ‘Ruby Blood’ sweet orange (C. sinensis L. Osbeck) + ‘Volkamer’ lemon, ‘Rohde Red’ sweet orange (C. sinensis L. Osbeck) + ‘Volkamer’ lemon, and ‘Valencia’ sweet orange + Fortunella obovata hort. ex Tanaka. For P. nicotianae trunk and root infection assays, plants of the somatic hybrids, obtained from 9-month semi-hardwood cuttings, were evaluated and compared with diploid citrus rootstock cultivars after mycelia inoculation in the trunk or spore infestation in the substrate, respectively. ‘Cleopatra’ mandarin + sour orange, ‘Rangpur’ lime + ‘Sunki’ mandarin, ‘Cleopatra’ mandarin + ‘Volkamer’ lemon, ‘Ruby Blood’ sweet orange + ‘Volkamer’ lemon, ‘Rohde Red’ sweet orange + ‘Volkamer’ lemon, and ‘Caipira’ sweet orange + ‘Volkamer’ lemon had less trunk rot occurrence, whereas the somatic hybrids ‘Cleopatra’ mandarin + ‘Volkamer’ lemon, ‘Cleopatra’ mandarin + sour orange, ‘Caipira’ sweet orange + ‘Volkamer’ lemon, and ‘Caipira’ sweet orange + ‘Rangpur’ lime were tolerant to root rot. For CTV assays, plants of the somatic hybrids along with tolerant and intolerant rootstocks were budded with a mild strain CTV-infected or healthy ‘Valencia’ sweet orange budwood. Differences in average scion shoot length indicated that the hybrids ‘Cleopatra’ mandarin + sour orange and ‘Valencia’ sweet orange + Fortunella obovata were intolerant to CTV.     

Identification of S-alleles in pear (Pyrus communis L.) cv. ‘Rocha’ and other European cultivars

In this work we report the cloning and identification of S-RNase alleles responsible for gametophytic self-incompatibility (GSI) of ‘Rocha’ pear and of 13 other European pear cultivars that might be used as its pollinators. Partial sequences of S-RNase alleles were amplified by PCR with specific primers hybridising in conserved regions of previously identified S-RNase alleles of Pyrus communis, cloned and sequenced and the S-genotype of eight pear cultivars was fully determined. Three cultivars (‘General Léclerc’ (SqSl), ‘Tosca’ (SbSl) and ‘Alexandrine Douillard’ (SbSk)) shared no S-alleles with ‘Rocha’ (SaSe) and shall be totally compatible with this cultivar. None of the cultivars analysed showed an identical amplification pattern to the one observed in ‘Rocha’, so the other cultivars shall be at least semi-compatible. One new allele was identified in P. communis cv. ‘Beurré d’Avril’ (designated as St). The determination of both S-RNase alleles of cvs ‘Rocha’, ‘Beurré Precoce Morettini’ (SeSk) and ‘Tosca’ and the identification of one S-RNase allele in cvs ‘Carapinheira’ (Sb), ‘Amêndoa’ (Se), ‘Pérola’ (Sk) and ‘Beurré d’Avril’ (St) are important contributions for the effort recently developed worldwide to establish groups of sexual compatibility among European pears.     

Horticultural performance of ‘Folha Murcha’ sweet orange onto twelve rootstocks

Despite its outstanding position, the Brazilian citriculture is established on a very limited pool of varieties that limits its expansion and restricts the fruit availability throughout the year. This situation determines the urgent necessity of developing alternative scion and rootstock cultivars, with good performance under local conditions. ‘Folha Murcha’ sweet orange (Citrus sinensis (L.) Osbeck) is a late-harvest cultivar, suitable both for the juice processing industry and the fresh fruit market, being described as tolerant to citrus canker (Xanthomonas citri subsp. citri Schaad et al.), and less affected by citrus variegated chlorosis (Xylella fastidiosa Wells et al.). A study was conducted in Bebedouro, São Paulo State, Brazil, to evaluate the horticultural performance of ‘Folha Murcha’ sweet orange budded onto 12 rootstocks: the citrandarin ‘Changsha’ mandarin (Citrus reticulata Blanco) × Poncirus trifoliata ‘English Small’; the hybrid ‘Rangpur’ lime (Citrus limonia Osbeck) × ‘Swingle’ citrumelo (P. trifoliata (L.) Raf. × Citrus paradisi Macfad.); the trifoliates (P. trifoliata (L.) Raf.) ‘Rubidoux’, ‘FCAV’, and ‘Flying Dragon’ (P. trifoliata var. monstrosa); the ‘Sun Chu Sha Kat’ mandarin (C. reticulata Blanco); the ‘Sunki’ mandarin (Citrus sunki (Hayata) Hort. ex. Tanaka); the ‘Rangpur’ limes (C. limonia Osbeck) ‘Cravo Limeira’ and ‘Cravo FCAV’; ‘Carrizo’ citrange (C. sinensis × P. trifoliata), ‘Swingle’ citrumelo (P. trifoliata × C. paradisi), and ‘Orlando’ tangelo (C. paradisi × Citrus tangerina cv. ‘Dancy’). The experimental grove was planted in 2001, using a 7 m × 4 m spacing, in a randomized block design, with five replications and two plants per plot. No supplementary irrigation was applied. Fruit yield, canopy volume, tree tolerance to drought and to citrus variegated chlorosis, and fruit quality were assessed for each rootstock. Trees grafted onto the ‘Flying Dragon’ trifoliate were smaller in size, but had largest yield efficiency when compared to those grafted onto other rootstocks. Lower alternate bearing index was observed on trees budded onto ‘Cravo FCAV’ ‘Rangpur’ lime. Both ‘Rangpur’ lime rootstocks and the ‘Sunki’ mandarin induced higher tree tolerance to drought. The ‘Flying Dragon’ trifoliate induced better fruit quality and higher tolerance to citrus variegated chlorosis (CVC) to ‘Folha Murcha’ trees. A cluster multivariate analysis identified three groups of rootstocks with similar effects on ‘Folha Murcha’ tree performance. Among the 12 evaluated rootstocks, the ‘Flying Dragon’ trifoliate has a unique effect on plant growth, tolerance to drought and CVC, fruit yield and fruit quality of ‘Folha Murcha’ trees, and may be better suited for high-density plantings.     

Effect of 2,4-d, glutamine and BAP on embryogenic suspension culture of date palm (Phoenix dactylifera L.)

The proliferation of embryogenic suspension culture in two cultivars (Jihel and Bousthami Noir) of Phoenix dactylifera L. was tested on liquid media with or without 2,4-d and with different glutamine concentrations (3.35 × 10⁻⁴, 6.7 × 10⁻⁴ and 13.4 × 10⁻⁴ M). The liquid medium with 0.1 mg l⁻¹ 2,4-d and 6.7 × 10⁻⁴ M glutamine has clearly improved the proliferation of somatic embryos. In fact, when glutamine concentration increased from 3.35 × 10⁻⁴ to 6.7 × 10⁻⁴ M, the yield of somatic embryos increased from 14 to 56 embryos per 100 ml of culture medium for “Jihel” cultivar and 25–71 embryos per 100 ml of culture medium for “Bousthami Noir” cultivar. In contrast, increasing glutamine concentration from 6.7 × 10⁻⁴ to 13.4 × 10⁻⁴ M, the embryos yield was negligible. Based on biochemical analysis, the highest accumulation of proteins and sugars was obtained in liquid medium with 0.1 mg l⁻¹ 2,4-d and 6.7 × 10⁻⁴ M glutamine (118 and 91 mg of proteins g⁻¹ DW, respectively, for “Jihel” and “Bousthami Noir” cultivars; 194 mg of sugars g⁻¹ DW for “Jihel” cultivar and 182 mg of sugars g⁻¹ DW for “Bousthami Noir” cultivar). In addition, the supply of 0.05 mg l⁻¹ BAP on the germination medium could be useful in terms of germination percentage of somatic embryos. When BAP concentration increased from 0.05 to 0.2 mg l⁻¹, the germination percentage of somatic embryos decreased from 14.2 to 4.9%, while secondary embryogenesis increased from 26.4 to 45.2%.     

Changes in fox squirrel anti-predator behaviors across the urban–rural gradient

Predator stimuli created by humans in the urban environment may alter animals’ anti-predator behaviors. I hypothesized that habituation would cause anti-predator behaviors to decrease in urban settings in response to humans. Additionally, I hypothesized that populations habituated to humans would show reduced responses to other predator stimuli. I observed three populations of squirrels (urban, suburban and rural) responses to human approaches, red-tailed hawk vocalizations (Buteo jamaicensis) and coyote (Canis latrans) vocalizations. Mahalanobis distances of anti-predator behaviors in response to human approaches were consistent with the urban–rural gradient. Flight initiation distances (X ² = 26.33, df = 2, P < 0.001) and amount of time dedicated to anti-predator behavior (X ² = 10.94, df = 2, P = 0.004) in response to human approaches were also consistent with the urban–rural gradient. Supporting the habituation hypothesis, naive juvenile squirrels increased flight initiation distances (X ² = 35.89, df = 1, P < 0.001) and time dedicated to anti-predator behaviors (X ² = 9.46, df = 1, P = 0.002) relative to adult squirrels in the same urban environment. Time dedicated to anti-predator behaviors differed among all three sites in response to both coyote (X ² = 9.83, df = 2, P = 0.007) and hawk (X ² = 6.50, df = 2, P = 0.035) vocalizations. Responses to both vocalizations on rural sites (coyote = 45%, hawk = 55%) greater than twice that found on the urban sites (coyote = 11%, hawk = 20%). This is possibly the first case of a transfer of habituation demonstrated under field conditions.     

Production of inter-section hybrids between Primula filchnerae and P. sinensis through ovule culture

Inter-section hybrids were obtained in the reciprocal crosses between Primula filchnerae (2n = 2x = 24) of Sect. Pinnatae and P. sinensis ‘Fanfare’ (2n = 2x = 24) of Sect. Auganthus by rescuing ovules on half-strength (1/2) Murashige and Skoog's (MS) medium supplemented with 50 g l⁻¹ sucrose, 2.5 g l⁻¹ gellan gum, 0.1 mg l⁻¹ α-naphthaleneacetic acid (NAA), 0.1 mg l⁻¹ 6-benzyladenine (BA) and 50 mg l⁻¹ gibberellic acid (GA₃). In ovule culture, germination occurred with radicle elongation but no plumule was observed. The radicle kept on the initial medium showed root proliferation with callus formation. When the calluses were transferred to (1/2)MS media containing 30 g l⁻¹ sucrose and 3 g l⁻¹ gellan gum, without plant growth regulators (PGRs) or with 1 mg l⁻¹ zeatin and 0.1 mg l⁻¹ NAA, plantlets were regenerated. The plants thus obtained were confirmed to be hybrids through flow cytometry (FCM) and random amplified polymorphic DNA (RAPD) analyses. The hybrid obtained when P. filchnerae was used as the maternal parent was diploid, whereas hexaploid hybrid was obtained when using P. sinensis as the maternal parent. The hexaploid hybrid might be produced through chromosome doubling of a triploid originated from the fertilization of P. sinensis with unreduced pollen of P. filchnerae.     

Effects of the commercial product based on Trichoderma harzianum on plant,bulb and yield characteristics of onion

Effects of the commercial product TrichoFlow WP™ (Agrimm Technologies Ltd., New Zealand), based on the fungus Trichoderma harzianum, on quality characteristics and yield of bulb onion was investigated. Bulb sets of the local cultivar Kantartopu was planted in soil with in and between row distances of 0.15 m and 0.40 m, respectively. The product, at considerably high dosages of 5 g m⁻², 10 g m⁻² and 15 g m⁻², was mixed with water and sprinkled once to the plots at planting. Analyses of data at harvest did not show statistical significance for Trichoderma effect on total bulb yield, bulb diameter, leaf length, number of shoot apex, %titratable acidity, number of internal (fleshy) leaves, number of external (papery) leaves, %soluble solids and %bulbs with diameters of 20–39 mm, 40–69 mm and ≥70 mm. The yields obtained from the plots treated with the dosages of 5 g m⁻², 10 g m⁻² and 15 g m⁻² and the control plots were 1063.7 kg da⁻¹, 1051.0 kg da⁻¹, 1066.5 kg da⁻¹ and 985.0 kg da⁻¹, respectively. Our results showed that high dosages of the Trichoderma product were not effective in enhancing onion bulb and yield characteristics under the given conditions.