Superando problemas de extracción de ADN de plantas carnívoras

We tested previously published protocols for DNA isolation from plants with high contents of polyphenols and polysaccharides for several taxa of carnivorous plants. However, we did not get satisfying results with fresh or silica dried leaf tissue obtained from field collected or greenhouse grown plants, nor from herbarium specimens. Therefore, we have developed a simple modified protocol of the commercially available Macherey- Nagel NucleoSpin® Plant kit for rapid, effective and reproducible isolation of high quality genomic DNA suitable for PCR reactions. DNA extraction can be conducted from both fresh and dried leaf tissue of various carnivorous plant taxa, irrespective of high contents of polysaccharides, phenolic compounds and other secondary plant metabolites that interfere with DNA isolation and amplification.Probamos algunos protocolos publicados previamente para el aislamiento del ADN de plantas con alto contenido de polifenoles y polisacáridos para varios táxones de plantas carnívoras. Sin embargo, no conseguimos muy buenos resultados ni con tejidos de hojas frescas, ni con tejidos de hojas secadas en gel de sílice obtenidas de plantas colectadas en el campo o cultivadas en los invernaderos, ni de especímenes de herbario. Por lo tanto, hemos desarrollado un protocolo sencillo, modificado del Macherey- Nagel NucleoSpin® Plant kit disponible en el mercado para el aislamiento rápido, eficaz y reproducible de ADN genómico de alta calidad conveniente para la reacción en cadena de la polimerasa. La extracción del ADN se puede realizar en tejidos de hojas frescas o secas de varios táxones de plantas carnívoras, sin importar el grado de contenido de polisacáridos, compuestos fenólicos u otros metabolitos secundarios que interfieren con el aislamiento y la amplificación del ADN

Crop load ifluences fruit quality of young ‘Golden Delicious’ apples

Istraživanja utjecaja opterećenja rodom na generativnu aktivnost, te kakvoću plodova, obavljena su tijekom 1998-1999. godine sa sortom ‘Golden Delicious’, cijepljenom na podlozi M9. Voćke su bile posađene u proljeće 1997. godine na razmaku 3,0 x 0,8 m (4166 stabala/ha) i uzgajane kao super vreteno. Na osnovi lipanjskog otpadanja plodića u 1998. godini voćke u pokusu smo podijelili u tri skupine: s niskim (A), srednjim (B) i visokim (C) početnim rodnim potencijalom. U 1998. godini voćke u skupini A opterećene su s 5, u skupini B s 15, te u skupini C s 25 plodova na stablo. U 1999. godini unutar svake skupine bila su tri opterećenja: 40, 60 i 80 plodova/stablo (nisko, srednje i visoko opterećenje). Rezultati dobiveni tijekom dvogodišnjeg istraživanja ukazuju na značajan utjecaj opterećenja rodom na prirod i kakvoću plodova. Najbolji rezultati glede priroda i kakvoće plodova ostvareni su kod svih pokusnih skupina (A, B i C) uz umjereno opterećenje rodom. Stoga se u intenzivnom uzgoju jabuke moraju prikladno opteretiti rodom, a posebice u razdoblju ulaska u punu rodnost.Investigations into the effect of crop load on yield and fruit quality of young apple ‘Golden Delicious’, grafted on M9 rootstock was conducted in years 1998-1999. The orchard was planted in the spring 1997, at a spacing of 3.0 x 0.8 m (4166 trees/ha) and trained to super spindle. On the basis of the rate of natural fruit drop in the second growing year, three experimental groups were established, classified as trees of low (A), medium (B) and high initial productivity (C). In that year crop load was regulated by hand thinning in group A to 5, in group B to 15 and in group C to 25 fruits/tree. In the third growing year crop load was regulated to three levels (low, medium and high) equally in all groups (40, 60 and 80 fruits/tree). The results showed significant effect of crop load on yield and fruit quality. The best results were obtained in all groups when crop load was medium. This result illustrates the importance of regulating fruit load in the intensive apple orchards, particularly during tree establishment

Crop load ifluences fruit quality of young ‘Golden Delicious’ apples

Istraživanja utjecaja opterećenja rodom na generativnu aktivnost, te kakvoću plodova, obavljena su tijekom 1998-1999. godine sa sortom ‘Golden Delicious’, cijepljenom na podlozi M9. Voćke su bile posađene u proljeće 1997. godine na razmaku 3,0 x 0,8 m (4166 stabala/ha) i uzgajane kao super vreteno. Na osnovi lipanjskog otpadanja plodića u 1998. godini voćke u pokusu smo podijelili u tri skupine: s niskim (A), srednjim (B) i visokim (C) početnim rodnim potencijalom. U 1998. godini voćke u skupini A opterećene su s 5, u skupini B s 15, te u skupini C s 25 plodova na stablo. U 1999. godini unutar svake skupine bila su tri opterećenja: 40, 60 i 80 plodova/stablo (nisko, srednje i visoko opterećenje). Rezultati dobiveni tijekom dvogodišnjeg istraživanja ukazuju na značajan utjecaj opterećenja rodom na prirod i kakvoću plodova. Najbolji rezultati glede priroda i kakvoće plodova ostvareni su kod svih pokusnih skupina (A, B i C) uz umjereno opterećenje rodom. Stoga se u intenzivnom uzgoju jabuke moraju prikladno opteretiti rodom, a posebice u razdoblju ulaska u punu rodnost.Investigations into the effect of crop load on yield and fruit quality of young apple ‘Golden Delicious’, grafted on M9 rootstock was conducted in years 1998-1999. The orchard was planted in the spring 1997, at a spacing of 3.0 x 0.8 m (4166 trees/ha) and trained to super spindle. On the basis of the rate of natural fruit drop in the second growing year, three experimental groups were established, classified as trees of low (A), medium (B) and high initial productivity (C). In that year crop load was regulated by hand thinning in group A to 5, in group B to 15 and in group C to 25 fruits/tree. In the third growing year crop load was regulated to three levels (low, medium and high) equally in all groups (40, 60 and 80 fruits/tree). The results showed significant effect of crop load on yield and fruit quality. The best results were obtained in all groups when crop load was medium. This result illustrates the importance of regulating fruit load in the intensive apple orchards, particularly during tree establishment

Contrasting Dihydronaphthoquinone Patterns in Closely Related Drosera (Sundew) Species Enable Taxonomic Distinction and Identification

Dihydronaphthoquinones are described as constituents of sundews (Drosera), Venus flytraps (Dionaea), and dewy pines (Drosophyllum) for the first time. As in the corresponding naphthoquinones, these reduced derivatives may occur in two regio-isomeric series distinguished by the relative position of a methyl group (at position 2 or 7 in the naphthalene skeleton), depending on the taxon. Species producing plumbagin (2-methyljuglone, 1) do commonly contain the corresponding dihydroplumbagin (5), while species containing ramentaceone (7-methyljuglone, 2) also contain dihydroramentaceone (7-methyl-β-dihydrojuglone, 6). So far, only few species containing plumbagin (1) and dihydroplumbagin (5) additionally form dihydroramentaceone (6) but not ramentaceone (2). Thus, subtle but constant differences in the chemism of closely related and morphologically similar species reliably define and distinguish taxa within D. sect. Arachnopus, which is taken to exemplify their chemotaxonomic utility. The joint presence of quinones and hydroquinones allows observations and predictions on the chemical structures and the reactions of these intriguing natural products

REDČENJE PLODIČEV JABLANE PRI SORTI ‘ZLATI DELIŠES’ Z UPORABO ETEFONA, NAA IN BA TER NJIHOVIH KOMBINACIJ

Thinning of ‘Golden Delicious’ apples was studied after single application of ethephon 200 ppm at the balloon stage, of naphthaleneacetic acid (NAA) 10 ppm or benzyladenine (BA) 100 ppm at 10 mm fruit diameter, after sequential application of ethephon followed by NAA or/and BA or tank mixed NAA + BA application. The single application of ethephon, NAA or BA, as well as the sequential application of ethephon applied fi rst at the balloon stage and NAA or BA applied at 10 mm fruitlet diameter did not cause a signifi cant reduction of fi nal crop load nor did it cause an increase of the mean fruit weight. The treatment of tank mixed application NAA + BA at 10 mm fruit diameter and, similarly, the treatment of sequential spray of ethephon followed by tank mixture of NAA + BA had both a signifi cant effect on thinning in the studied year with the signifi cant reduction of fi nal fruit retention and the signifi cant enhancement of fruit weight. No additional thinning due to the ethephon application happened in the sequential treatments when ethephon was applied fi rst and NAA + BA mixture was applied afterward.Proučevali smo redčenje plodičev jablane pri sorti ‘Zlati delišes’ pri samostojni aplikaciji sredstev za redčenje plodičev (etefon 200 ppm v stadiju balona, NAA 10 ppm ali BA 100 ppm v stadiju velikosti plodičev 10 mm) ter pri kombiniranih aplikacijah sredstev, kjer je bil najprej apliciran etefon, nato pa še NAA ali BA, kjer sta bila NAA in BA združena v škropilni mešanici in kjer je aplikaciji etefona nato sledila še aplikacija NAA in BA združena v škropilni mešanici. Samostojna aplikacija etefona 200 ppm v stadiju balona, kakor tudi samostojna aplikacija NAA 10 ppm oziroma BA 100 ppm v stadiju velikosti plodičev 10 mm ni imela statistično značilnega vpliva na redčenje plodičev, ker ni povzročila značilnega zmanjšanja števila plodov ob obiranju, kakor tudi ne značilnega povečanja velikosti plodov. Podoben rezultat brez statistično značilnega učinka na redčenje plodičev je bil dobljen pri obravnavanjih s kombinacijo sredstev, kjer je bil najprej apliciran etefon v balonskem stadiju, nato pa še NAA oziroma BA pri velikosti plodičev 10 mm. Edini statistično značilen vpliv na redčenje plodičev je bil dosežen pri obravnavanju, kjer so bila sredstva NAA in BA nanešena skupaj kot škropilna mešanica pri velikosti plodičev 10 mm, kakor tudi pri obravnavanju z zaporedno kombinacijo sredstev, najprej etefona, nato pa NAA + BA v škropilni mešanici. Iz rezultatov kombiniranih nanosov je razvidno, da predhodni nanos etefona v času cvetenja ni imel vpliva na kasnejša redčenja z NAA ali BA, niti kadar sta bila nanešena samostojno, niti kadar sta bila nanešena kot škropilna mešanica

On-line estimation of biomass through pH control analysis in aerobic yeast fermentation systems

The amount of acid or base consumed in yeast cultures has been recently assigned to the pathway of nitrogen assimilation under respiratory conditions with no contribution by carbon metabolism (Castrillo et al., 1995). In this investigation, experiments under respirofermentative conditions have shown that production or consumption of ethanol does not contribute significantly to the specific rate of proton production (qH+), thus extending the previously obtained relationships for all aerobic conditions in which other major acid/base contributions are not involved. Tests in batch and chemostat culture confirm the validity of qH+ as a formal control parameter in aerobic fermentations.Junta Nacional de Investigação Científica e Tecnológica Gobierno Vasco (Departamento de Educación, Universidadese Investigación) Ministerio de Educación y Ciencia-Acciones Integrada

Breeding systems of floral colour forms in the Drosera cistiflora species complex

The study was supported by the National Research Foundation of South Africa (Grant 46372 to SDJ).Variation in plant breeding systems has implications for pollinator‐mediated selection on floral traits and the ecology of populations. Here we evaluate pollinator contribution to seed production, self‐compatibility and pollen limitation in different floral colour forms of Drosera cistiflora sensu lato (Droseraceae). These insectivorous perennial plants are endemic to fynbos and renosterveld vegetation in the Cape Floristic Region of South Africa, and the species complex includes five floral colour forms (pink, purple, red, white and yellow), some of which are known to be pollinated by beetles. Controlled hand‐pollination experiments were conducted in 15 populations of D. cistiflora s.l. (two to four populations per floral colour form) to test whether the colour forms vary in their degree of self‐compatibility and their ability to produce seeds through autonomous self‐fertilization. Yellow‐flowered forms were highly self‐incompatible, while other floral colour forms exhibited partial self‐compatibility. Seed set resulting from autonomous selfing was very low, and pollinator dependence indices were high in all populations. Since hand cross‐pollination resulted in greater seed set than open pollination in 13 of the 15 populations, we inferred that seed production is generally pollen‐limited.Drosera cistiflora s.l. typically exhibits high levels of pollinator dependence and pollen limitation. This is unusual among Drosera species worldwide and suggests that pollinators are likely to mediate strong selection on attractive traits such as floral colour and size in D. cistiflora s.l. These results also suggest that the floral colour forms of D. cistiflora s.l. which are rare and threatened are likely to be vulnerable to local extinction if mutualisms were to collapse indefinitely.PostprintPeer reviewe