scholarly journals Influence of plant growth stage on resistance to anthracnose in Andean lupin (Lupinus mutabilis)

2015 ◽  
Vol 66 (7) ◽  
pp. 729 ◽  
Author(s):  
Cesar E. Falconi ◽  
Richard G. F. Visser ◽  
Sjaak van Heusden
Keyword(s):  
Developmental Stages ◽  
Main Stem ◽  
Colletotrichum Acutatum ◽  
Leaf Stage ◽  
Lupinus Mutabilis ◽  
Early Seedling ◽  
Flower Stage ◽  
Necrotic Spots ◽  
Lateral Branches ◽  
Plant Pathogen Interactions

Anthracnose, caused by Colletotrichum acutatum, is the most destructive fungal disease of Andean lupin (Lupinus mutabilis Sweet) in Ecuador and of other lupin species around the world. Symptoms of necrotic spots occur throughout the main stem, and infection progresses to cause bending of the main stem and lateral branches, resulting in yield loss. Although there is no known anthracnose resistance, this study aims to assess tolerance of Andean lupin and investigate lupin–C. acutatum interactions. Two Andean lupin genotypes, I-450 Andino and I-451 Guaranguito, were inoculated on the meristematic section of the main stem, either by spraying or by pipetting C. acutatum spores on to an artificial wound. Although the two methods gave similar results, spraying is the preferred method because it mimics natural pathogen infection. Plant-pathogen interactions were assessed at five different phenological stages (leaf stages 2–3, 4–5, 6–7, 8–9, and 10–11) with three C. acutatum isolates by using a 0–5 scale to assess disease symptoms. In both genotypes, anthracnose symptoms were greater at early seedling stage (2–3-leaf stage), decreasing significantly in early vegetative phase (6–7-leaf stage) and increasing again when the flower stage began (10–11-leaf stage). However, the tolerance of these two Andean lupin genotypes to anthracnose was not equally expressed at all developmental stages. We recommend, in a breeding program, that screening for anthracnose first occurs at the 6–7-leaf stage (6 weeks old) and again when flowering starts at the 10–11-leaf stage (10 weeks old) so that the overall tolerance can be determined. This method could be used in lupin breeding programs for improving resistance to anthracnose.

Chemical manipulation of Leptosphaeria maculans (blackleg disease) pseudothecial development and timing of ascospore discharge from canola (Brassica napus) residues

2003 ◽  
Vol 54 (9) ◽  
pp. 837 ◽  
Author(s):  
A. D. Wherrett ◽  
K. Sivasithamparam ◽  
M. J. Barbetti
Keyword(s):  
Developmental Stages ◽  
Severe Disease ◽  
Leptosphaeria Maculans ◽  
Potential Method ◽  
Chemical Treatments ◽  
Ascospore Discharge ◽  
Significant Difference ◽  
Significant Efficacy ◽  
Early Seedling ◽  
Disease Pressure

A study was carried out to establish key developmental stages of Leptosphaeria maculans on canola residues leading up to ascospore discharge and how these stages could be affected by chemicals. The residues were dipped in a range of chemicals, including fungicides, herbicides, and surfactants, to determine possible manipulative effects of the chemicals on the development of the fungus including ascospore discharge. Treated residues were placed in the field during the growing season. Ascospore discharge was found to be closely related to pseudothecial maturity and density. There was no significant difference between pseudothecial maturation on the crown component compared with the stem component. A high correlation between rainfall and pseudothecial density suggested that rainfall was a good complimentary indicator for timing of ascospore discharge. These results may provide the canola industry with a potential method of monitoring pseudothecial development for estimating disease hazards. This would allow manipulation of sowing times so as to minimise or avoid heavy ascospore showers coinciding with the early seedling phase. Twenty chemical treatments showed significant efficacy in decreasing ascospore numbers early in the season, most often by delaying the development of the pseudothecia on the residues. Two scenarios were formulated giving growers the potential to manipulate pseudothecial development and/or ascospore discharge. Firstly, a number of chemicals, such as fluquinconazole, technical grade flutriafol, and gluphosinate-ammonium, were able to delay pseudothecial development and subsequent ascospore discharge was decreased by 100%, 99%, and 96%, respectively. This scenario gives growers the potential to minimise synchronisation of ascospore discharge with early crop establishment. Secondly, a situation where pseudothecial development is not delayed, but number of ascospores discharged is reduced (e.g. ziram by 45%) would only be effective if the reduction resulted in a less severe disease epidemic. There is significant potential for development of commercial chemical treatments of residues to reduce disease pressure on seedlings.

scholarly journals Floral Scent Emission from Nectaries in the Adaxial Side of the Innermost and Middle Petals in Chimonanthus praecox

2018 ◽  
Vol 19 (10) ◽  
pp. 3278 ◽  
Author(s):  
Zhineng Li ◽  
Yingjie Jiang ◽  
Daofeng Liu ◽  
Jing Ma ◽  
Jing Li ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Floral Scent ◽  
Flower Bud ◽  
Adaxial Side ◽  
Open Flower ◽  
Qrt Pcr ◽  
Relative Expression Level ◽  
Flower Stage ◽  
Chimonanthus Praecox ◽  
Deciduous Shrub

Wintersweet (Chimonanthus praecox) is a well-known traditional fragrant plant and a winter-flowering deciduous shrub that originated in China. The five different developmental stages of wintersweet, namely, flower-bud period (FB), displayed petal stage (DP), open flower stage (OF), later blooming period (LB), and wilting period (WP) were studied using a scanning electron microscope (SEM) to determine the distribution characteristics of aroma-emitting nectaries. Results showed that the floral scent was probably emitted from nectaries distributed on the adaxial side of the innermost and middle petals, but almost none on the abaxial side. The nectaries in different developmental periods on the petals differ in numbers, sizes, and characteristics. Although the distribution of nectaries on different rounds of petals showed a diverse pattern at the same developmental periods, that of the nectaries on the same round of petals showed some of regularity. The nectary is concentrated on the adaxial side of the petals, especially in the region near the axis of the lower part of the petals. Based on transcriptional sequence and phylogenetic analysis, we report one nectary development related gene CpCRC (CRABS CLAW), and the other four YABBY family genes, CpFIL (FILAMENTOUS FLOWER), CpYABBY2, CpYABBY5-1, and CpYABBY5-2 in C. praecox (accession no. MH718960-MH718964). Quantitative RT-PCR (qRT-PCR) results showed that the expression characteristics of these YABBY family genes were similar to those of 11 floral scent genes, namely, CpSAMT, CpDMAPP, CpIPP, CpGPPS1, CpGPPS2, CpGPP, CpLIS, CpMYR1, CpFPPS, CpTER3, and CpTER5. The expression levels of these genes were generally higher in the lower part of the petals than in the upper halves in different rounds of petals, the highest being in the innermost petals, but the lowest in the outer petals. Relative expression level of CpFIL, CpCRC, CpYABBY5-1, and CpLIS in the innermost and middle petals in OF stages is significant higher than that of in outer petals, respectively. SEM and qRT-PCR results in C. praecox showed that floral scent emission is related to the distribution of nectaries.

scholarly journals L-DOPA Trends in Different Tissues at Early Stages of Vicia faba Growth: Effect of Tyrosine Treatment

2018 ◽  
Vol 8 (12) ◽  
pp. 2431 ◽  
Author(s):  
Claudia Oviedo-Silva ◽  
Mhartyn Elso-Freudenberg ◽  
Mario Aranda-Bustos
Keyword(s):  
Amino Acid ◽  
Vicia Faba ◽  
High Performance ◽  
Developmental Stages ◽  
Growth Effect ◽  
Guaiacol Peroxidase ◽  
Nonprotein Amino Acid ◽  
Early Seedling ◽  
Gpx Activity ◽  
Different Tissues

The nonprotein amino acid Levo-3,4-dihydroxyphenylalanine (L-DOPA) has insecticidal, allelochemical, and antiparkinsonian effects. The aim of this research was to assess L-DOPA content in different tissues of Vicia faba (cv. Super Agua Dulce), and to verify if treatment with the phenolic amino acid L-4-hydroxyphenylalanine (tyrosine) had an effect on such content. Under light germination, control and tyrosine-treated early seedling stages of V. faba were studied and L-DOPA was quantified spectrophotometrically (Arnow’s method) and by high-performance thin-layer chromatography (HPTLC), as well. Additionally, tyrosinase (TYROX) and guaiacol peroxidase (GPX) activities (considered markers of a phenolic compounds metabolism) were quantified as germination proceeded. Different organs (roots, sprouts, and seeds) and different developmental stages were considered. Steady high L-DOPA concentrations were found in untreated sprouts and roots compared to seeds, as time progressed. While TYROX activity was not detected in these experiments, GPX had diverse trends. In control tissues, GPX increased in seed tissue as germination progressed, whereas in roots and sprouts, a decreasing GPX activity was observed. Tyrosine exposure decreased L-DOPA content, and decreased or did not change GPX activity (depending on the organ). Both Arnow’s and HPTLC methods were consistent in terms of tendencies, except for the scarce contents found in seeds, in which HPTLC was more sensitive. The richest source of L-DOPA was found in shoots (untreated), reaching as high as 125 mg g−1 DW (12% in DW) (the highest content reported in fava bean seedlings until now), whereas the smallest L-DOPA content was found in seeds. The importance of light germination conditions is discussed in terms of L-DOPA yield and from a physiological perspective. It is concluded that V. faba (cv. Super Agua Dulce) shoots are a good source of L-DOPA and that tyrosine addition (0.55 mM) decreases L-DOPA content in actively growing tissues (shoots and roots).

SEPTORIA CANKER OF INTRODUCED AND NATIVE HYBRID POPLARS

1939 ◽  
Vol 17c (6) ◽  
pp. 195-204 ◽  
Author(s):  
J. E. Bier
Keyword(s):  
North American ◽  
Main Stem ◽  
Leaf Injury ◽  
Hybrid Poplars ◽  
Septoria Musiva ◽  
Lateral Branches

Studies have shown that Septoria musiva Peck, a North American fungus which occurs commonly as a leaf-spotting parasite on native poplars, produces cankers, in addition to leaf injury, on certain introduced poplars (Populus Rasumowskyana Schneid., P. Petrowskyana Schneid., and P. berolinensis Dipp.), and the native hybrids, Northwest and Saskatchewan poplar.Field observations and inoculation experiments demonstrated that most of the inoculum for spring infection arises from ascospores of a Mycosphaerella stage, and that the fungus enters the stems through mechanical wounds uninjured lenticels, leaf petioles, or stipules. Incipient cankers occur in the bark of the current year's wood, soon girdling leading and side shoots. They later spread from lateral branches into the main stem, developing into perennial cankers which ultimately girdle and kill the trees.

scholarly journals Evaluation of Morphological Traits Associated with Productivity in F1 Interspecific (Cucurbita maxima Duch. x C. moschata Duch.) Hybrid Processing Squash

HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1156-1163 ◽  
Author(s):  
Jake Uretsky ◽  
J. Brent Loy
Keyword(s):  
Interspecific Hybrids ◽  
Morphological Traits ◽  
Canopy Cover ◽  
Female Parent ◽  
Main Stem ◽  
Stem Length ◽  
Cucurbita Maxima ◽  
Fresh Market ◽  
Greenhouse Study ◽  
Lateral Branches

Interspecific hybrids can be produced from certain cross combinations of Cucurbita maxima x C. moschata. These hybrids have been used extensively as rootstocks for melon and watermelon grafting, but only occasionally for fresh market use. The objective of this study was to assess the potential of interspecific hybrids for use in pie processing in terms of morphological traits related to productivity. We used a bush-processing inbred line of C. maxima, NH65, as the female parent and two vining-processing cultivars of C. moschata, Long Island Cheese (LIC) and Dickinson Field (DF) as pollen parents to produce two interspecific hybrids with large orange fruit, potentially suitable for processing. A greenhouse study was conducted to compare internode lengths, main stem diameters, flowering patterns, and leaf area at first appearance of female flowers in NH65, LIC, DF, and two interspecific hybrids, NH65xLIC and NH65xDF. Plants were grown in 8.7 L nursery pots, watered and fertigated with drip tubing, and trellised to a single main stem. In LIC and DF, internode lengths increased rapidly beyond the fourth node before reaching a maximum by node 12. Internodes in NH65 did not exceed 3 cm until node 15, and average lengths never exceeded 4 cm. In interspecific hybrids, internode lengths mimicked bush plants for 6 or 7 internodes, remaining below 3 cm, but then increased rapidly to lengths approaching that of the vining cultivars after internode 10. Staminate flowers were more abundant than pistillate flowers in NH65, LIC and DF; whereas the interspecies hybrids produced primarily pistillate flowers. In NH65xLIC, the first pistillate flowers appeared on nodes 9–11, on average 38.3 days after transplanting (DAT), and in NH65xDF, on nodes 9–17, 42.3 DAT. First pistillate flowers in NH65 occurred on nodes 9–11, 34.3 DAT, compared with nodes 9–13, 39.3 DAT and nodes 17–21, 50.0 DAT, respectively, for LIC and DF. A field study was conducted for comparing flowering patterns and growth habits in NH65xLIC, NH65xDF, DF, LIC, NH65, and ‘Golden Delicious’ (GD), a popular C. maxima processing winter squash. Stem length was short and petioles highly elongated in the two interspecific hybrids until about 34 DAT, such that plants exhibited a uniform, compact phenotype similar to NH65. Subsequently, stems elongated rapidly, with lengths approaching and occasional exceeding those in vine cultivars. In the two vining C. moschata cultivars, LIC and DF, 4–6 laterals developed near the base of plants, usually consisting of 12–30 nodes. NH65xLIC produced mostly short laterals (4–15 nodes) interspersed along much of the main stem, whereas NH65xDF produced numerous lateral branches, mostly ranging from 11 to 30 nodes long, between the base and about the halfway point along the main stem. Mature leaves were about twice as large in the two interspecific hybrids as in DF and GD; this together with differences in early growth habit and branching patterns contributed to a much faster leaf canopy cover in the interspecific hybrids in comparison with the vining cultigens.

scholarly journals Fasulyede Büyüme ve Gelişme Dönemleri

2014 ◽  
Vol 3 (2) ◽  
pp. 84 ◽  
Author(s):  
Ramazan İlhan Aytekin ◽  
Sevgi Çalışkan
Keyword(s):  
Phaseolus Vulgaris ◽  
Seed Development ◽  
Plant Development ◽  
Developmental Stages ◽  
Bean Plant ◽  
Main Stem ◽  
Vegetative Stage ◽  
Biological Cycle ◽  
Phaseolus Vulgaris L ◽  
Pod Development

Uniform description of developmental stages in crops improve communication among producers, researchers and others. A standardized, accurate, and easy system is needed to describe bean (Phaseolus vulgaris L.) plant development. The objective of this study was to develop and describe stages of bean plant development in a manner which is simple but accurate. The biological cycle of the bean plant is divided into two successive phases: the vegetative stage (V) and the reproductive stage (R). Vegetative stages are determined by counting the number of trifoliolate leaves (V1 to VN) on the main stem beginning above the unifoliate leaf. Reproductive stages R1 and R2 are based on flowering, R3 and R4 on pod development, R5 and R6 on seed development, and R7, R8 and R9 on maturation.

scholarly journals Evidence of protandry in Aa Rchb.f. (Orchidaceae, Cranichideae)

Lankesteriana ◽  
2011 ◽  
Vol 11 (3) ◽  
Author(s):  
Delsy Trujillo ◽  
Thassilo Franke ◽  
Reinhard Agerer
Keyword(s):  
Cell Death ◽  
Developmental Stages ◽  
Ventral Side ◽  
Dorsal Side ◽  
Upward Movement ◽  
Downward Movement ◽  
Self Pollination ◽  
Flower Stage ◽  
Male Phase ◽  
Early Flower

Protandry has been described in orchids since Darwin (1862) as a strategy to promote cross-pollination. Three different forms of protandry have been reported in tribe Cranichideae: downward movement of the labellum in Spiranthes species, upward movement of the column in Sauroglossum elatum Lindl. and Manniella spp., and downward movement of the column in Prescottia stachyodes (Sw.) Lindl. In the present work, through longitudinal and transverse sections of flowers of different developmental stages, we reported column movement of Aa erosa (Rchb.f.) Schltr. and the mechanism responsible for the movement. Our result shows that in an early flower stage (male phase), the column of Aa erosa is straight. The gradual cell death of the dorsal side of the column and size increase of the cells of the ventral side cause the column to bend downward to almost 90o representing the female stage. Some authors have suggested self-pollination in Aa. But flies exploring inflorescences of Aa species have been observed in the field by the author. This observation plus the evidence of protandry in Aa erosa could discard self- pollination as the only strategy of pollination in this genus. 

scholarly journals Poinsettia Stem Strength

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 484A-484 ◽  
Author(s):  
Jeff S. Kuehny ◽  
Patricia Branch
Keyword(s):  
Plant Growth ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Nitrogen Fertilizer ◽  
Plant Growth Regulator ◽  
Main Stem ◽  
Stem Strength ◽  
Lateral Branches ◽  
Fertilizer Rates ◽  
Drip Fertigation

Lateral branches of poinsettia tend to break from the main stem as plants reach maturity. The cause of poor stem strength is not known; however, suggested factors implicated in poor stem strength are: rate of nitrogen fertilizer used, type of plant growth regulator used, crowding of plants, or stem diameter of the cutting. Four different experiments were conducted to determine if these factors affected stem strength of poinsettia. Experiment 1: `Freedom Red', `Success', `V-17 Angelika Red', `Red Sails', `Nutcracker Red', `Cortez', `Maren', and `Red Splendor' poinsettia were fertilized with 20N–1P0–20K at 75, 75/125, 125/200, or 200 ppm N drip fertigation with zero leachate. Experiment 2: Three plant growth regulators were applied to `Pearl' and `Jolly Red' poinsettias. Experiment 3: `Freedom Red' plants were grown in a 625, 900, 1225, or 1600 cm2 area. Experiment 4: Rooted `Freedom Red' cuttings with stem diameters of 4.5, 5.5, 6.5, or 7.5 mm were used. A force meter was used to determine the strength of each lateral on the main stem of the six replications in each experiment. The lower laterals had the least stem strength and the top lateral had the highest stem strength for all treatments in all experiments. The stem strengths of some cultivars in experiment 1 were stronger at the lower fertilizer rates. Type of plant growth regulator had no significant affect on most poinsettia cultivars. The stem strengths of poinsettias in experiments 3 and 4 varied according to which lateral was measured.

scholarly journals First Report of Colletotrichum acutatum on Strawberry in Northwestern Argentina

Plant Disease ◽  
2000 ◽  
Vol 84 (6) ◽  
pp. 706-706 ◽  
Author(s):  
C. J. Ramallo ◽  
L. D. Ploper ◽  
M. Ontivero ◽  
M. P. Filippone ◽  
A. Castagnaro ◽  
...  
Keyword(s):  
Colletotrichum Acutatum ◽  
Conidial Suspension ◽  
Disease Symptoms ◽  
Northwestern Argentina ◽  
First Report ◽  
Surface Control ◽  
Detached Leaves ◽  
Strawberry Anthracnose ◽  
Pathogenicity Tests ◽  
Necrotic Spots

Isolates were obtained from strawberry tissue with anthracnose symptoms from several locations near Tucumán, Argentina. Isolates were characterized using several criteria. Isolates produced fusiform conidia, tapered to a point at both ends, and averaged 13.5 × 4.9 μm. On potato dextrose agar, colonies produced a white cottony mycelial colony that turned orange in older cultures. Compared with Colletotrichum fragariae, the new isolates produced fewer appressoria. Pathogenicity tests were conducted on detached leaves and plants in the greenhouse and field. Detached immature leaves of cvs. Chandler, Fern, and Sweet Charlie were inoculated with a 20-μl droplet of an aqueous conidial suspension (106 conidia per ml) placed on the adaxial surface. Control leaves were inoculated with sterile distilled water. Leaves were maintained under white light (2,000 lux, 12 h/day) at 26°C, and 100% relative humidity. Necrotic spots were visible 4 days after inoculation. Greenhouse and field plants were spray-inoculated and covered for 48 h. Disease symptoms were mainly observed on petioles and runners 9 days after inoculation. No lesions were observed on control detached leaves or plants. Koch's postulates were confirmed in all cases. Based on morphological and cultural characteristics, isolates were identified as C. acutatum Simmonds (1). This is the first report of C. acutatum causing strawberry anthracnose in northwestern Argentina. Reference: (1) B. Smith and L. L. Black. Plant Dis. 74:69, 1990.

Field environment studies on lupins. 2. The effects of time of planting on dry matter partition and yield components of Lupinus angustifolius L

1975 ◽  
Vol 26 (5) ◽  
pp. 809 ◽  
Author(s):  
MW Perry
Keyword(s):  
Seed Yield ◽  
Yield Components ◽  
Dry Matter ◽  
Planting Date ◽  
Main Stem ◽  
Systematic Effect ◽  
Structural Development ◽  
Vegetative Development ◽  
Field Environment ◽  
Lateral Branches

Dry matter partition, seed yield, and yield components were examined in two lupin cultivars at eight planting times. Dry matter production and seed yield both declined with later planting primarily as a result of the foreshortened growing season which reduced the production of lateral branches and consequently the number of inflorescences per plant. For a given inflorescence, planting date appeared to have no systematic effect on pod number, although pod numbers on the main stem inflorescence varied with planting date. Mean seed weight declined slightly with later planting. Unicrop, the earlier-flowering cultivar, gave higher seed yields owing to greater development of higher order lateral branches and heavier individual seeds. Flowering began when only 17-25 % of maximum dry matter had accumulated, and subsequent dry matter partition between main stem and successive orders of lateral branches emphasized the characteristic structural development of the lupin. Seed filling occurred in the last 4-6 weeks of growth when vegetative development had nearly ceased, and was almost concurrent in both cultivars, all planting times and all lateral orders irrespective of the time of pod set.

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