Consequences of Corymbia (Myrtaceae) hybridisation on leaf-oil profiles

The present study examines patterns of heritability of plant secondary metabolites following hybridisation among three genetically homogeneous taxa of spotted gum (Corymbia henryi (S.T.Blake) K.D.Hill & L.A.S.Johnson, C. citriodora subsp. variegata (F.Muell.) K.D.Hill & L.A.S.Johnson and C. citriodora (Hook.) K.D.Hill & L.A.S.Johnson subsp. citriodora (section Maculatae), and their congener C. torelliana (F.Muell.) K.D.Hill & L.A.S.Johnson (section Torellianae)). Hexane extracts of leaves of all four parent taxa were statistically distinguishable (ANOSIM: global R = 0.976, P = 0.008). Hybridisation patterns varied among the taxa studied, with the hybrid formed with C. citriodora subsp. variegata showing an intermediate extractive profile between its parents, whereas the profiles of the other two hybrids were dominated by that of C. torelliana. These different patterns in plant secondary-metabolite inheritance may have implications for a range of plant-insect interactions.

Eriophyid mites on spotted gums: population and histological damage studies of an emerging pest

A suite of co-occurring eriophyid mite species are significant pests in subtropical Australia, causing severe discolouration, blistering, necrosis and leaf loss to one of the region's most important hardwood species, Corymbia citriodora subsp. variegata (F. Muell.) K. D. Hill & L. A. S. Johnson (Myrtaceae). In this study, we examined mite population dynamics and leaf damage over a 1-year period in a commercial plantation of C. citriodora subsp. variegata. Our aims were to link the incidence and severity of mite damage, and mite numbers, to leaf physical traits (moisture content and specific leaf weight (SLW)); to identify any seasonal changes in leaf surface occupancy (upper vs. lower lamina); and host tree canopy strata (upper, mid or lower canopy). We compared population trends with site rainfall, temperature and humidity. We also examined physical and anatomical changes in leaf tissue in response to mite infestation to characterize the plants' physiological reaction to feeding, and how this might affect photosynthesis. Our main findings included positive correlations with leaf moisture content and mite numbers and with mite numbers and damage severity. Wet and dry leaf mass and SLW were greater for damaged tissue than undamaged tissue. Mites were distributed equally throughout the canopy and on both leaf surfaces. No relationships with climatic factors were found. Damage symptoms occurred equally and were exactly mirrored on both leaf surfaces. Mite infestation increased the overall epidermal thickness and the number and size of epidermal cells and was also associated with a rapid loss of chloroplasts from mesophyll cells beneath damage sites. The integrity of the stomatal complex was severely compromised in damaged tissues. These histological changes suggest that damage by these mites will negatively impact the photosynthetic efficiency of susceptible plantation species.

Postharvest physiology and volatile production by flowers of Ptilotus nobilis

Ptilotus nobilis (Lindl.) F. Muell. has potential in the floriculture industries as a cut flower crop. Ethylene production and respiration rates, fresh weight changes and volatile scent production from cut inflorescences of P. nobilis cultivars Passion (dark pink flowers) and Purity (white-green flowers) were measured during vase life. Inflorescence weight loss was significant (P<0.001) during vase life with wilting and colour loss being the primary reasons for loss of vase life. Inflorescences ready for the cut market stored and at 22 degrees C had vase lives of >12 d. Ethylene production by inflorescences was low to negligible. Treatment with silverthiosulphate (STS) and ethylene had no effects on vase life. Evidently, ethylene did not play a role in determining the postharvest longevity of cut P. nobilis flowers. Respiration rates of inflorescences were high at harvest (>700 mg CO2 kg(-1) FW h(-1)) and declined gradually there-after during vase life. Total volatile emissions followed a similar pattern. For Passion, respiration rates of immature florets were significantly greater (P=0.02) than florets from other developmental stages while the calyx produced the most CO2. For Purity, respiration rates of florets of different maturities did not differ and the reproductive tissue produced the most CO2. Only fully opened mature florets with their stigma and anthers revealed, emitted significant quantities of volatiles (P<0.001) and primarily from the calyx tissue for both cultivars. The individual volatiles differed somewhat for the two cultivars. However, both produced significant quantities of benzaldehyde, 3,5-dimethoxytoluene and benzyl alcohol. These. compounds have previously been associated with desirable floral scent. (C) 2013 Elsevier B.V. All rights reserved.

Boronia heterophylla vase life is influenced more by ethylene than by bacterial numbers or vase solution pH

Bacterial proliferation in both vase solutions and in cut flower stems has been implicated in reducing the vase life of numerous genera. Boronia heterophylla F. Muell. (Red Boronia) vase life was assessed at two stages of floral maturity for nine vase solution treatments covering a pH range of 2.5-5.7. Vase life for advanced harvest maturity stems ranged from 4.2 d in 10 mM citric acid + 50 mg L-1 chlorine (pH 2.5) to 12.9 d after STS pulsing (pH 5.7). For normal harvest maturity stems, the corresponding range was 5.8-19.0 d, respectively. Vase solutions containing 50 mg L-1 chlorine biocide resulted in decreased longevity. In contrast, pulsing with the ethylene-binding inhibitor, STS, significantly increased vase life. The number of bacteria in the vase solutions after 11 d was determined in stems of advanced maturity. The solution with the greatest number of bacteria, 4.0 x 10(10) cfu mL(-1), was water used after STS pulsing and in which the flowers lasted longest. Vase solution bacteria were enumerated on days 0,3, 6, 9 and 12 of the vase period with stems of normal harvest maturity. There was no relationship between vase life and vase solution bacterial numbers ((R) over bar (2) = 0.000). Moreover, there was a negative relationship between numbers of bacteria in basal 0-5 cm stem segments and vase life. As no correlations were evident between longevity and either the pH or vase solution bacterial numbers, B. heterophylla vase life was evidently limited principally by ethylene action. (C) 2013 Elsevier B.V. All rights reserved.

Germinating the seeds of three species of Pimelea sect. Epallage (Thymelaeaceae)1

Pimelea trichostachya Lindl., P. simplex F.Muell. and P. elongata Threlfall frequently cause pimelea poisoning of cattle. Fresh seeds of these species, belonging to sect. Epallage (Endl.) Benth. of Pimelea Gaertn. (Thymelaeaceae) are strongly dormant for years when in laboratory storage. Common methods of stimulating germination, such as scarification, dry heat and cold stratification, did not remove much of the dormancy. ‘Smoke water’ stimulated some germination but its effect was unpredictable and many seedlings then grew aberrantly. Exposure of imbibed seeds to gibberellic acid greatly and reliably improved the germination of all three species. However, the manner of application and the concentration of gibberellic acid used had to be appropriate or many young seedlings grew abnormally or died suddenly, limiting successful plant establishment rates. The dormancy type involved is non-deep Type 2 physiological. Ten days of good moisture, in addition to gibberellic acid exposure, is required before appreciable laboratory germination occurs at optimal temperatures. Thus, the mechanism by which gibberellic acid stimulates good germination does not appear to be the same as that which primes seeds for the rapid and prolific germination often seen under natural conditions in arid Australia. Seeds of P. simplex subsp. continua (J.M.Black) Threlfall proved most difficult to germinate and those of P. elongata the easiest.

Postharvest physiology and volatile production by flowers of Ptilotus nobilis

Ptilotus nobilis (Lindl.) F. Muell. has potential in the floriculture industries as a cut flower crop. Ethylene production and respiration rates, fresh weight changes and volatile scent production from cut inflorescences of P. nobilis cultivars Passion (dark pink flowers) and Purity (white-green flowers) were measured during vase life. Inflorescence weight loss was significant (P < 0.001) during vase life with wilting and colour loss being the primary reasons for loss of vase life. Inflorescences ready for the cut market stored and at 22 °C had vase lives of >12 d. Ethylene production by inflorescences was low to negligible. Treatment with silverthiosulphate (STS) and ethylene had no effects on vase life. Evidently, ethylene did not play a role in determining the postharvest longevity of cut P. nobilis flowers. Respiration rates of inflorescences were high at harvest (>700 mg CO2 kg−1 FW h−1) and declined gradually thereafter during vase life. Total volatile emissions followed a similar pattern. For Passion, respiration rates of immature florets were significantly greater (P = 0.02) than florets from other developmental stages while the calyx produced the most CO2. For Purity, respiration rates of florets of different maturities did not differ and the reproductive tissue produced the most CO2. Only fully opened mature florets with their stigma and anthers revealed, emitted significant quantities of volatiles (P < 0.001) and primarily from the calyx tissue for both cultivars. The individual volatiles differed somewhat for the two cultivars. However, both produced significant quantities of benzaldehyde, 3,5-dimethoxytoluene and benzyl alcohol. These compounds have previously been associated with desirable floral scent.

Postharvest physiology and volatile production by flowers of Ptilotus nobilis

Ptilotus nobilis (Lindl.) F. Muell. has potential in the floriculture industries as a cut flower crop. Ethylene production and respiration rates, fresh weight changes and volatile scent production from cut inflorescences of P. nobilis cultivars Passion (dark pink flowers) and Purity (white-green flowers) were measured during vase life. Inflorescence weight loss was significant (P < 0.001) during vase life with wilting and colour loss being the primary reasons for loss of vase life. Inflorescences ready for the cut market stored and at 22 °C had vase lives of >12 d. Ethylene production by inflorescences was low to negligible. Treatment with silverthiosulphate (STS) and ethylene had no effects on vase life. Evidently, ethylene did not play a role in determining the postharvest longevity of cut P. nobilis flowers. Respiration rates of inflorescences were high at harvest (>700 mg CO2 kg−1 FW h−1) and declined gradually thereafter during vase life. Total volatile emissions followed a similar pattern. For Passion, respiration rates of immature florets were significantly greater (P = 0.02) than florets from other developmental stages while the calyx produced the most CO2. For Purity, respiration rates of florets of different maturities did not differ and the reproductive tissue produced the most CO2. Only fully opened mature florets with their stigma and anthers revealed, emitted significant quantities of volatiles (P < 0.001) and primarily from the calyx tissue for both cultivars. The individual volatiles differed somewhat for the two cultivars. However, both produced significant quantities of benzaldehyde, 3,5-dimethoxytoluene and benzyl alcohol. These compounds have previously been associated with desirable floral scent.

Tripogon loliiformis elicits a rapid physiological and structural response to dehydration for desiccation tolerance

Resurrection plants can withstand extreme dehydration to an air-dry state and then recover upon receiving water. Tripogon loliiformis (F.Muell.) C.E.Hubb. is a largely uncharacterised native Australian desiccation-tolerant grass that resurrects from the desiccated state within 72 h. Using a combination of structural and physiological techniques the structural and physiological features that enable T. loliiformis to tolerate desiccation were investigated. These features include: - (i) a myriad of structural changes such as leaf folding, cell wall folding and vacuole fragmentation that mitigate desiccation stress; - (ii) potential role of sclerenchymatous tissue within leaf folding and radiation protection; - (iii) retention of ~70% chlorophyll in the desiccated state; - (iv) early response of photosynthesis to dehydration by 50% reduction and ceasing completely at 80 and 70% relative water content, respectively; - (v) a sharp increase in electrolyte leakage during dehydration, and; - (vi) confirmation of membrane integrity throughout desiccation and rehydration. Taken together, these results demonstrate that T. loliiformis implements a range of structural and physiological mechanisms that minimise mechanical, oxidative and irradiation stress. These results provide powerful insights into tolerance mechanisms for potential utilisation in the enhancement of stress-tolerance in crop plants.

Assessment Method for Leaf Litters Allelopathic Effect on Cyanobacteria

A new bioassay technique combining leaf disk and softagar over-layer methods was developed to investigate the allelopathic effect of deciduous leaf litters on the growth of cyanobacteria ( Microcystis aeruginosa Kütz.). Bioactive substances exuded from leaf disks caused inhibitory plaques on the agar plate containing cyanobacteria , and the rate of diffusion depended on the specific leaf disk area. Most of the leaf litters collected around reservoirs in Japan showed inhibitory activity to M. aeruginosa , with Rhus trichocarpa Miq., Quercus variabilis Blume and Mallotus japonicus (Thunb.) Muell. Arg. being the strongest among the 22 tested species.(PDF has 4 pages.)

中国柳叶藓科植物的研究－分类、区系和生态

柳叶藓科（Amblystegiaceae）是侧蒴藓类中一个较大的科，世界报导有 39 属，约 300 余种。由于其配子体特征受环境影响较大，其属种的分类位置历来存有争论。中国记载有柳叶藓科 115 个分类单位，己知 23 属，67 种，12 变种，3 变型（Redfearn, et al. 1996），其记录和标本鉴定比较混乱。因此，对中国柳叶藓科全面系统的分类、区系和生态研究，对深入了解中国苔藓植物多样性及特点有重要的科学意义。作者在大量文献查阅和考证后，对国外 9 个主要苔藓植物标本馆的有关中国柳叶藓科 47 份模式标本和标本 300 余份，国内 6 个主要标本馆的 3，000余份标本进行了全面系统的形态解剖学和分类学研究，对孢子和蒴齿的形态特征进行了扫描电镜观察。并采用等级聚类分析方法，对其属种间的系统关系、地理分布特点和区系成分定量研究。同时，在国内首次开展了藓类专科的生态学研究，在吉林长白山、黑龙江五营、辽宁白石砬子和医巫闾山保护区进行样方调查，对样方以及柳叶藓科植物与环境因子的关系进行了典范对应分析。研究的主要结果有：1. 对中国柳叶藓科进行系统分类的结果是共记录 19 属 46 种 5 变种。对每一分类单位给予形态特征描述和绘图，并利用 Arcview 软件绘制其中国分布图。发现中国新分布记录植物 3 种，1 变种：圆叶湿原藓 Calliergon megalophyllum Mikut, 毛叶镰刀藓 Drepanocladus trichophyllus (Warnst.) Podp, 细肋镰刀藓 Drepanoclaldus tenuinervis Kop. 和牛角藓宽肋变种 Cratoneuron filicinum var. atrovirens (Brid.) Ochyra。归并 Campylium amblystegioides Broth. (=Isopterygium minutirameum), Leptodictyum serrulatum Broth. (=Eurhychium pulchellum), Drepanophyllaria cuspidarioides C. Muell. ( = Hygroamblystegium tenax), Amblystegiella yuennanensis Broth. (= Platydictya jungermannioides) 和 Amblystegium schesianum C. Muell., Hygroamblystegium ramulosum Dixon, Cratoneuron longicosatatum Bai X.-L. (Cratoneuron filicinum) 7 个新同物异名，并纠正 9 个前人错误记录。2. 电镜扫描观察结果孢子大都近球形，通常无萌发孔，具近极薄壁区。纹饰皆由周壁形成，一般呈规则或不规则颗粒状、疣状或瘤状，区别在于孢子大小，颗粒或瘤或疣的大小、高度以及密集程度等。孢蒴多为长柱形，弯曲，只有三洋藓的孢蒴形态变化较大。藓齿两层为灰藓型蒴齿。齿毛数量和发育程度各异。总的来说，柳叶藓科植物的孢子体特征在属间或种间差别不大。3. 系统关系的等级聚类分析结果支持了近年来对柳叶藓科植物修订的某些属的概念。如传统上定义很广的细湿藓属（包括狭义的细湿藓属、嗜湿藓属和偏叶藓属）和水灰藓属在聚类树状图中常不聚合在一起。说明了广义细湿藓属的水灰藓属不是一个很自然的分类类群，而应该分为更细的属。柳叶藓属、湿柳藓属和薄网藓属的种类明显常聚在一起，位置较近，且比较稳定，可以同归于柳叶藓属。毛叶镰刀藓与范氏藓和大范氏藓的关系较近，说明适合将毛叶镰刀藓归并入范氏藓属中，范氏藓属和湿原藓属的较近。4. 对中国柳叶藓科的地理分布和区系成分的聚类分析表明，该科为典型的泛北极分布类型，大多分布于北半球的温带和寒带，59％为欧亚美共有种，14％为东亚特有成分，其中 8％ 为中国特有成分。属种的分布特点主要是，牛角藓属、柳叶藓属、细湿藓属、嗜湿藓属、三洋藓属和水灰藓属的中国分布比较广泛，大湿原藓属和偏叶藓属主要分布在东北地区和西南高山地区，而湿原藓属、范氏藓属和镰刀藓属则主要分布在东北地区。总的来说，气候较为寒冷的东北地区是中国柳叶藓科植物的主要分布区。西南地区的种类也较为丰富，是柳叶藓科植物的中国特有属种的分化中心。其他地区的柳叶藓样植物大多是分布在高山地区，表现出地区商的不平衡性。5. 对东北地区柳叶藓科植物的生态调查和典范对应分析研究进一步说明，柳叶藓科多分布于阴湿或水生生境，喜中性的酸碱条件。湿原藓属、范氏藓属、和镰也藓属植物常分布于沼泽，其中范氏藓属和镰藓属的一些种类常沉水或半沉水生长，而其他种类能分布于相对较干燥或季节性积水的地方。牛角藓属和水灰藓属植物常分布于溪流中，牛角藓属常分布于泉水或溪流的源头，而水灰藓属则喜流动的溪流。细湿藓属，柳叶藓属和嗜湿藓属植物的生境较为干燥，既能在林下土生、石生或树干生，也能分布于较为潮湿的生境。三洋藓常见于森林林下，在有些开阔地带也能生长分布，其生境范围明显较柳叶藓科其他各类为广，是唯一能适应陆生环境的柳叶藓科植物。对柳叶藓科植物与其环境因子的进行的典范对应分析结果表明，所研究的 26 种柳叶藓科植物大部分分布于水生环境，因其在排序图中与基质含水量接近。与基质含沙量、草本层郁蔽的相关也较大。其中水生环境下的 19 种柳叶藓科植物与水流速度和水体 pH 值关系较密切。

有关中国细齿缺萼苔(Gymnomitrioncrenulatum)和中华缺萼苔(G.sinense)资料

细齿缺萼苔 (G .crenulatumGott.exCarr.)的中国记录为错误鉴定 ,标本实为中华缺萼苔(G .sinenseK .Muell.) ,应被移出中国苔藓植物区系。研究发现了多号西藏产中华缺萼苔标本 ,将中华缺萼苔其在中国的分布范围从云南的模式产地扩展到了西藏。对中华缺萼苔进行了形态特征描述和分布分析 ,并提供了特征示意图

中国合叶苔属(Scapania)两个新记录种

报道了于我国四川发现的苔类植物合叶苔属(Scapania)的中国2个新记录种;兜瓣合叶苔(Scapania cuspiduligera(Nees)K.Muell.)和长叶合叶苔(Scapania glaucocephala(Tayl)Aust.)。

Desempenho de clones de seringueira sob diferentes sistemas de sangria.

Este trabalho teve como objetivo avaliar o crescimento e a producao da borracha de clones seringueira [Havea brasiliensis ( Wild. Ex Adr. De Juss.) Muell. Arg.] sob diferentes sistemas de sangria, em condição de Cerrado dos Municipios de Barro Alto Goianesia no Estado de Goais. O plantio foi feito em fevereiro de 1992, no espacamento de 8,0 x 2,5 m (500 plantas/ha), em talhoes de 8 a 10 hectares para cada um dos clones RRIM 600, GT 1, PB 217, PB 235, PR 107 e PR 255 os quais receberam as mesmas praticas de manejo. Aos oito anos de idade, foram feitas as seguintes avaliacoes: estande final; circunferencia do caule a 1,20 m do solo; porcentagens de plantas aptas a sangria; producao de borracha acumulada na caneca pesada mensalmente; incidencia de seca de painel. A producao foi avaliada em nove sistemas de sangria em meia espiral (1/2 S), praticados cinco dias por semana (5d/7) e 10 meses ao ano (10m/12), variando na frequência de sangria (d/4 e d/7 = a cada 4 e 7 dias), a concentracao de Ethephon (ET 0,25%, 2,5%,3,3% e 5,0%) e sua frequencia de aplicacao durante o periodo chuvoso ( a cada 22, 28 e 35 dias), como segue: 1) 1/2S, d/7, ET 2,5% a cada 22 dias; 2)1/2S, d/7, ET 2,5% a cada 30 dias (referncia); 3) 1/2S. d/4, ET 2,5% a cada 30 dias; 4) 1/2S, d/7, ET 3,3% a cada 22 dias; 5)1/2S, d/7, ET 3,3% a cada 30 dias; 6) 1/2S. d/7, ET 5,0% a cada 22 dias 7) 1/2S, d/7, ET 5,0% a cada 30 dias; 8) 1/2S, d/7, ET 5,0% a cada 35 dias; 9) 1/2S, d/7, ET 0,25% (pulverizando 10 ml por painel) a cada 22 dias. Nos sistemas 1 a 8, o Ethephon foi pincelado ( 1mL) na canaleta de corte e ate 2 cm acima dela (Pa e La). O delineamento experimental foi de blocos ao acaso, com quatro repeticoes de 10 plantas poe parcela. Cada clone constitui um experimento separado, sendo os resultados de producao acumulada anual submetidos a analise de variancia e, nos caso de significancia, as medias dos sistemas foram comparadas pelo teste Tukey, ao nível de 5% de probabilidade. Nao foi constatada qualquer incidencia de seca de painel e os resultados possibilitaram as seguintes conclusoes para as condicoes da regiao: 1) o sistema 1/2S, d/7, ET 2,5% a cada 30 dias e o mais indicado par a sangria dos clones PR 255, PR 107, PB 235, PB 217 e GT 1; 2) o sistema 1/2S, d/7, ET 3,3% a cada 30 dias e o mais indicado para a sangria do clone RRIM 600; 3) a producao individual de borracha em kg/planta/ano e maior nos clones RRIM 600, PB 217 e PR 255, enquanto a producao total em kg/ha/ano e superior nos clones RRIM 600 e PB 235; 4)os clones PB 217 e PR 255 sao menos adaptados a regiao, apresentando menores valores de estande final, circunferencia do caule, porcentagem de plantas em sangria e de producao total de borracha por hectare.

Characterization of Wastes from Natural Rubber and Rubber Wood Processing Industries and Their Utilization for Biomethanation

The research work which was carried out to characterization of wastes from natural rubber and rubber wood processing industries and their utilization for biomethanation. Environmental contamination is an inevitable consequence of human activity. The liquid and solid wastes from natural rubber based industries were: characterized and their use for the production of biogas investigated with a view to conserve conventional energy, and to mitigate environmental degradation.Rubber tree (flevea brasiliensis Muell. Arg.), is the most important commercial source of natural rubber and in india. Recently, pollution from the rubber processing factories has become very serious due to the introduction of modern methods and centralized group processing practices.The possibility of the use of spent slurry as organic manure is discussed.l0 percent level of PSD, the activity of cellulolytic, acid producing,proteolytic, lipolytic and methanogenic bacteria were more in the middle stage of methanogenesis.the liquid wastes from rubber processing used as diluents in combination with PSD, SPE promoted more biogas production with high methane content in the gas.The factors that favour methane production like TS, VS, cellulose and hemicellulose degradation were favoured in this treatment which led to higher methane biogenesis.The results further highlight ways and means to use agricultural wastes as alternative sources of energy.