scholarly journals The optimized shape of a leaf petiole

Author(s):  
D. Pasini ◽  
V. Mirjalili
Keyword(s):  
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 478e-479
Author(s):  
M.M. Jenderek ◽  
A.J. Olney

Hibiscus syriacus is a difficult species in micropropagation due to its endogenous contamination and recalcitrant shoot formation; therefore, studies on using explants other than shoot tip or axillary buds of growing shrubs were initiated. Three different seedling fragments (root, hypocotyl, and leaf petiole) from aseptically germinated seedlings of hibiscus (var. Aphrodite) were evaluated for adventitious bud formation, shoot and leaf development. The explants were cultured on McCown's woody plant basal salt medium supplemented with KNO3 (800 mg/L), adenine sulfate (80 mg/L) and MS vitamins containing BA or 2iP or TDZ at 0.5, 1.0, 2.2, 4.4 and 10 mM. Adventitious buds were present on all of the three different explants grown on medium containing TDZ; however, the most abundant bud formation, with many small leaves originating from callus was observed on hypocotyl explants cultured on medium with 1 mM of TDZ. Petiole explants were the most frequent to develop short shoots (≈15 mm) and one to nine leaves without callus formation, where 70% of hypocotyl and the root explants formed leaves originating from callus. Callus was induced on all explant types regardless of the level or type of cytokinin used. However, the number of shoots produced by any explant type was low, petioles cultured on 0.5 and 1mM of TDZ were the most suitable material for non-callus shoot development in H. syriacus. Hypocotyl explants proved to be an excellent source for adventitious bud formation but their ability to develop shoots needs to be investigated.


Author(s):  
T. Baby ◽  
F.J. Moroni ◽  
P. Gascon‐Aldana ◽  
N.C. Moroni ◽  
B.P. Holzapfel ◽  
...  

Author(s):  
Tamara Popović ◽  
Jelena Menković ◽  
Anđelka Prokić ◽  
Nevena Zlatković ◽  
Aleksa Obradović

AbstractIn Montenegro, stone fruit species are grown on intensive and semi-intensive commercial plantations. However, almond production is mainly organized on family gardens and for household consumption. During two seasons (2017–2018), we surveyed apricot, peach, nectarine, sweet cherry, Japanese plum, and almond orchards for the presence of bacterial diseases at different geographical locations in Montenegro. From leaf, petiole and fruit lesions, branch or twig cankers, and necrotizing buds, a total of 29 isolates were obtained and subjected to identification based on their morphological, pathogenic, biochemical, and molecular characteristics. Pathogenicity of the isolates was confirmed by reproducing the symptoms on leaves, fruits, and twigs of the corresponding host plants. The biochemical tests indicated that the isolates belong to Pseudomonas syringae. However, isolates’ characterization showed variation in their phenotypic and molecular features. The presence of the syrB gene and ice nucleation activity grouped most of the isolates within pathovar syringae. The results of rep-PCR using the BOX primer revealed high genetic diversity of isolates. Multilocus sequence analysis (MLSA), using four housekeeping genes, showed that 27 isolates belong to the genomic species 1, P. syringae sensu stricto, corresponding to P. syringae phylogroup 2. However, isolates from the same phylogroup 2 did not form a monophyletic group. One strain isolated from apricot was most distinct and similar to members of genomic species 2, phylogroup 3. All tested isolates showed significant levels of resistance to copper sulfate and high level of sensitivity to streptomycin sulfate in vitro.


1991 ◽  
Vol 69 (7) ◽  
pp. 1552-1556 ◽  
Author(s):  
M. Muntanola-Cvetković ◽  
Jelena Vukojević ◽  
M. Mihaljčević

The systemic nature of the disease of sunflower plants caused by Diaporthe helianthi, the leaf–petiole–stem route of the host invasion by the fungus, and the plant tissues that were successively affected were demonstrated through histological studies. After penetration into the host, the infection hyphae invade the intercellular spaces and terminal veinlets of the lamina and spread toward larger branches of the conducting system, the midrib, and the petiole. Xylem elements are invaded but are affected less by the fungus attack than the phloem and the parenchyma tissues, which disintegrate completely. Hyphae spread through the leaf axil to the tissues of the stem cortex, where pycnidia of the Phomopsis anamorph are initiated from internal masses of mycelium. Key words: systemic plant diseases, sunflower diseases, Diaporthe helianthi, Phomopsis helianthi.


1969 ◽  
Vol 17 (1) ◽  
pp. 81 ◽  
Author(s):  
GL Shah ◽  
BV Gopal

The structure and development of stomata on the vegetative and floral organs of Vigna unguiculata Walp., and the vegetative organs of Phaseolus radiatus L. and P. aconitifolius Jacq. are described. Paracytic, anisocytic, and anomocytic stomata are present on the same surface of different organs of the plants investigated except on the stem and petiole of V. unguiculata, the bract of P. radiatus, and the petiole, stipule, and stipel of P. aconitifolius where the last type is absent. Stomata with only one subsidiary cell are found on the leaf, petiole, sepal, and petal of V. unguiculata. Diacytic stomata occur on the stipel of P. radiatus and the stem, stipule, and stipel of P. aconitifolius. Paracytic stomata are by far the commonest on each organ. The frequency of different types of stomata on different organs in the plants investigated is tabulated. The ontogeny of different kinds of stomata on each organ is mesogenous, but the perigenous type may be found on the petal and pericarp of V. unguiculata and the stipule of P. radiatus. The variation in stomata is due to: (a) a diversity in stomatal types even on the same surface, and (b) an increase in the number of subsidiary cells. The subsidiary cells divide, or additional subsidiary cells are derived from adjacent epidermal cells. The present study also supports the inclusion of the species concerned in the tribe Phaseolae.


1970 ◽  
Vol 35 (3) ◽  
pp. 431-438 ◽  
Author(s):  
MS Islam ◽  
MM Rahman ◽  
T Hossain

Forty-four hyacinth bean genotypes were evaluated for different qualitative and quantitative characters during July 2005 to February 2006 at Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur. The genotypes showed considerable variations for most of the morpho-physical traits. Shape, size and colour of vein, leaf, petiole, stem, flower, pod and seed varied among the genotypes. Days to first flower ranged from 47.6 to 136.3 days indicating the presence of early variety. Individual pod weight varied from 1.47 (HB042) to 12.3g (HB009). The genotype HB027 produced the maximum number of pods/ plant (425) closely followed by HB001 (385). Similar trend was observed for pod yield/plant. The genotype HB027 produced the highest pod yield/plant (3.45kg) followed by HB001 (3.35kg). 100-green seed weight ranged from 4.0g to 73.33g, which indicated the presence of bold seeded genotypes. Among the genotypes, HB027 and HB007 produced very bold green seed and higher green pod yield/plant, therefore, they can be selected for both pod and green seed production purpose. Keywords: Physico-morphological; hyacinth bean DOI: 10.3329/bjar.v35i3.6450Bangladesh J. Agril. Res. 35(3) : 431-438


2019 ◽  
Vol 6 (3) ◽  
pp. 127
Author(s):  
Cici Tresniawati ◽  
Nur Kholilatul Izzah ◽  
Ilham Nur Ardhi Wicaksono ◽  
Indah Sulistyorini ◽  
Edi Wardiana

<em>Candlenut [</em>Aleurites moluccana<em> (L.) Willd.</em><em>] is a perrenial plant that has high economic value. Information about vegetative and generative characters, as well as yield components that influence the yield is needed in the early stages of selection process in plant breeding.</em> <em>Selection of these characters can be done using Sequential Path Analysis (SPA) according to the plant development cycle, and then confirm the model using the Structural equation modeling (SEM) method. The aim of this study was to determine the vegetative characters and yield components that influence the candlenut production. The research was carried out at Pakuwon Experimental Station, Indonesian Industrial and Beverage Crops Research Institute, Sukabumi, from January to December 2018. Plant materials used in this study was 129 candlenut trees at 9 years old which were planted with a spacing of 10m x 10m. The data were analyzed using SPA followed by model confirmation using SEM method. The results showed that the production of seed was directly and positively influenced by the leaf petiole length, number of productive branches, seed weight, and number of fruits per tree, while the effect of stem height character is indirectly. Based on these results, plant selection based on vegetative characters such as leaf petiole length, number of productive branches, stem height character, number of fruits per tree and seed weight can be used to obtain high-yielding candlenut plants.</em>


Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 224-224 ◽  
Author(s):  
Q. Huang

Bacterial leaf scorch caused by Xylella fastidiosa has been reported in 17 species of oak including bur, pin, red, scarlet, shingle, and white oaks (3). In September 2002, a leaf scorch symptom characterized by marginal necrosis of leaves bordered by a darker brown band was observed in a mature black oak (Quercus velutina Lam.) at the U.S. National Arboretum in Washington, D.C. The leaf petiole of the black oak was processed in general extraction buffer (Agdia, Inc., Elkhart, IN) contained in a FastDNA lysing matrix tube using the FastPrep FP120 instrument (Qbiogene, Inc., Carlsbad, CA) (1). The leaf petiole extract reacted with an antiserum specific for X. fastidiosa (Agadia, Inc.) in an enzyme-linked immunosorbent assay (ELISA). A slow-growing bacterium was cultured from leaf petioles of the affected black oak tree by soaking the surface-sterilized, finely cut leaf petioles in sterile water for 30 min, followed by spreading the bacterial suspension on periwinkle wilt plates (1). When the cultured bacterium was subjected to polymerase chain reaction (PCR) with primers specific for X. fastidiosa (2), a 472-bp PCR product was detected. The PCR product was confirmed to be the predicted X. fastidiosa product by sequencing and sequence comparison with the reported genomic sequence of X. fastidiosa. ELISA and bacterial isolation from leaf petioles of a nearby symptomless white oak (Q. alba L.) tree were negative. To our knowledge, this is the first report of X. fastidiosa associated with leaf scorch in black oak in the United States, expanding the host range of the bacterium in economically important landscape tree species. References: (1) Q. Huang and J. L. Sherald. Curr. Microbiol. 48:73, 2004. (2) M. R. Pooler and J. S. Hartung. Curr. Microbiol. 31:377, 1995. (3) J. L. Sherald. Xylella fastidiosa, A bacterial pathogen of landscape trees. Page 191 in: Shade Tree Wilt Diseases, C. L. Ash, ed. The American Phytopathological Society, 2001.


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