scholarly journals Influence of mycorrhizal developmental stages and plant age on rhizosphere mycoflora of Pinus kesiya (Royle)

2014 ◽  
Vol 17 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
G. D. Sharma
Keyword(s):  
Developmental Stages ◽  
Sugar Content ◽  
Cunninghamella Elegans ◽  
Frequency Of Occurrence ◽  
Rhizopus Nigricans ◽  
Pinus Kesiya ◽  
Mycorrhizal Association ◽  
Mycorrhizal Roots ◽  
In The Beginning ◽  
Mycorrhizal Development

Quantitatively the population was recorded to be high around thc mycorrhizal roots. Some fungi were specific to different stages of mycorrhizal development. <i>Rhizopus nigricans</i> and <i>Cunninghamella elegans</i> were recorded at 5% mycorrhizal association stage. <i>Fusarium</i> sp. was found at 20% mycorrhizal association, while <i>Mucor</i> spp. were obtained at 60% stage. <i>Verticillium</i> sp. had the highest frequency of occurrence in the beginning of mycorrhizal association but later on <i>Penicilium</i> spp. were found to be the most common. Sugar content of mycorrhizal and nonmycorrhizal roots were determined to assess their effect on the mycorrhizospheric micropopulation. The mannitol and trehalose were present only in mycorrhizal roots.

scholarly journals Fluctuation patterns of different developmental stages of Helicoverpa armigera (Lepidoptera: Noctuidae) on chickpea (Cicer arietinum) and their relationship with the environment

2005 ◽  
Vol 16 (4) ◽  
Author(s):  
Zahid Ali Shah ◽  
Muhammad Shahzad
Keyword(s):  
Relative Humidity ◽  
Environmental Factors ◽  
Helicoverpa Armigera ◽  
Relative Frequency ◽  
Developmental Stages ◽  
Frequency Of Occurrence ◽  
Pod Borer ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae ◽  
Eggs And Larvae

The relative frequency of occurrence of different developmental stages of gram pod borer, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), and the dependence of its developmental stages on environmental factors, are crucial in the population management. The densities of eggs and larvae were low from December to mid-February due to prevailing cold. Owing to optimum environmental conditions, increasing densities were observed throughout March and they droppped again during the first week of April. The densities of eggs and different larval instars of H. armigera were significantly positively correlated with temperature, and significantly negatively correlated with the average morning relative humidity (RH;%) but not with the average evening RH (%).

Effect of three weeds on the growth and mycorrhizal infection of black walnut seedlings

1986 ◽  
Vol 64 (9) ◽  
pp. 1888-1892 ◽  
Author(s):  
Felix Ponder Jr.
Keyword(s):  
Seedling Growth ◽  
Dry Weight ◽  
Black Walnut ◽  
Mycorrhizal Infection ◽  
Greenhouse Experiments ◽  
Root Segments ◽  
Infected Root ◽  
Mycorrhizal Roots ◽  
Total Dry Weight ◽  
Mycorrhizal Development

The effect of unincorporated and incorporated litter and extracts of broom-sedge, fescue, and blackberry on the mycorrhizal development and growth of black walnut seedlings was investigated in two greenhouse experiments. Seedling growth varied with method of litter application. Only fescue extract decreased growth in the extract experiment, but unincorporated and incorporated broom-sedge litter significantly (P ≤ 0.05) reduced seedling total dry weight below that of mycorrhizal control seedlings. The total dry weight of seedlings in incorporated fescue litter was reduced by 47%. The number of mycorrhizal infected root segments on seedlings grown in unincorporated litter was more than twice the number of infected roots on seedlings grown in incorporated litters. Significantly fewer mycorrhizal roots were found on seedlings grown with fescue and broom-sedge litters than on mycorrhizal control seedlings. On the average, incorporation of litter increased the percentage of leaf phosphorus, but the shoot absorption of phosphorus was considerably less for seedlings grown in incorporated fescue litter compared with unincorporated fescue litter. Seedlings grown in fescue extract had 33% less phosphorus than control seedlings. Except for possible interference with mycorrhizal development when litter was incorporated, there was no evidence to suggest that blackberry litter contains substances that are allelopathic to black walnut.

EFFECTS OF ABIES GRANDIS RESIN ON THE ATTACK BEHAVIOR AND BROOD SURVIVAL OF SCOLYTUS VENTRALIS (COLEOPTERA: SCOLYTIDAE)

1970 ◽  
Vol 102 (10) ◽  
pp. 1229-1236 ◽  
Author(s):  
A. A. Berryman ◽  
M. Ashraf
Keyword(s):  
Developmental Stages ◽  
Flight Period ◽  
Attack Behavior ◽  
Resin Flow ◽  
Abies Grandis ◽  
Brood Survival ◽  
Early Developmental Stages ◽  
Flow Aggregation ◽  
In The Beginning ◽  
Early Developmental

AbstractScolytus ventralis females attack their host, Abies grandis, at random in the beginning of the flight period. The success of these attacks, as manifested by the length of the gallery, is determined by the rapidity of the host’s resinous response, attacking females being repelled by resin flow. Aggregation occurs on both resistant and susceptible hosts but is directly associated with the degree of gallery elongation. Resinosis occurring after brood establishment reduces survival, having its greatest impact on the early developmental stages. Mortality from resinosis is inversely related to attack density.

scholarly journals 464 Distribution of Sugars in Sweet Corn

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 524D-524
Author(s):  
V.M. Russo ◽  
T. Smith
Keyword(s):  
Zea Mays ◽  
Correlation Analysis ◽  
Plant Development ◽  
Developmental Stages ◽  
Sweet Corn ◽  
Sugar Content ◽  
The Other ◽  
Fresh Market ◽  
Leaf Stage ◽  
Corn Plants

Sweet corn (Zea mays L.) kernels are sinks, and sugars found in kernels must be translocated from a source. Stalk tissues can act as a source and a sink as sweet corn plants age. Quantity and types of sugars present in various sweet corn tissues during plant development are not well documented. Concentrations of fructose, glucose, sucrose, and their total were determined in the ninth stalk internodes (I9) from the 12-leaf stage (V12) to fresh-market maturity (R3) in sweet corn cultivars carrying either the su1se1, su1, or sh2 endosperm genotype. Developing ears were sampled at tassel emergence (VN) and silking (R1). Kernels and cob tissue were sampled separately at blister stage (R2) and R3. Correlation analysis was performed on concentrations of sugars at all developmental stages. In I9, from V12 to R3, levels of fructose and glucose declined and sucrose increased. In developing ears, concentrations of fructose and glucose increased from VN to R1. Concentrations of sugars in cobs in all cultivars were generally the same at R2 and R3. In kernels from R2 to R3 in the su1se1 cultivar, glucose decreased while the other sugars were unchanged; in the su1 cultivar, fructose decreased while levels of the other sugars stayed the same; and in the sh2 cultivar, fructose decreased, glucose was unchanged and sucrose increased. Correlation analysis suggested that the cultivars moved sugars to the kernels differently. The pattern of movement of sugars to kernels was most complex in the su1se1 cultivar than in the su1, which was more comlex than in the sh2 cultivar. Knowing how sugar content changes in the plant may be used to predict sugar content in kernels.

scholarly journals Flower opening and vase life of gladiolus cultivars: the sensitivity to ethylene and the carbohydrate content

2016 ◽  
Vol 22 (2) ◽  
pp. 147 ◽  
Author(s):  
Lucas Cavalcante Da Costa ◽  
Fernando Luiz Finger
Keyword(s):  
Developmental Stages ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Test Tube ◽  
Carbohydrate Content ◽  
Vase Life ◽  
Flower Opening ◽  
Total Soluble Sugars ◽  
Total Soluble Sugar

Vase life is one of the most important characteristics in the quality of cut flowers. The carbohydrate content of petals from each cultivar can be a decisive factor to vase life of gladiolus flowers. Despite exposure to ethylene does not affect the life of open florets of gladiolus flowers, it may reduce the flower’s commercial life due the occurrence of flower buds abortion. This study thus aimed to evaluate the flower opening and the vase life of gladiolus flowers according to ethylene sensitivity and carbohydrate content of each cultivar. The gladiolus cultivars used in Experiment I were  ‘Amsterdam’, ‘Blue Frost’, ‘Gold Field’, ‘Green Star’, ‘Jester’, ‘Lavender’, ‘Red Beauty’, ‘Rose Supreme’, ‘Traderhorn’, and ‘Verônica’. Stems were stored in airtight chambers and exposed to the ethylene concentrations of 0, 0.1, 1.0, 10, 100, and 1000 μL L−1 for 24 h. Subsequently, flower stem were placed in a test tube with distilled water when were evaluated for percentage of flower opening and vase life. In Experiment II, three cultivars (‘Amsterdam’, ‘Red Beauty’, and ‘Verônica’) were chosen based on the lowest, medium, and highest vase life in Experiment I, respectively. Total soluble sugars, reducing sugars, and starch contents were evaluated in five flower developmental stages. No effect of ethylene on the flower opening or alterations in flower opening between cultivars. The vase life of gladiolus flowers differed between cultivars regardless of ethylene action. ‘Verônica’ and ‘Amsterdam’, which had the highest and lowest vase life, respectively, differed as to the total soluble sugar content. Ethylene does not influence the flower opening or vase life of the gladiolus cultivars studied. In these cultivars, the maintenance of flower opening is attributed to total soluble sugars content, which, in turn, is a major determinant of the vase life.

Soil and fertilizer phosphorus: Effects on plant P supply and mycorrhizal development

2005 ◽  
Vol 85 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Cynthia Grant ◽  
Shabtai Bittman ◽  
Marcia Montreal ◽  
Christian Plenchette ◽  
Christian Morel
Keyword(s):  
Crop Yield ◽  
Management Practices ◽  
Phosphorus Uptake ◽  
Arbuscular Mycorrhizal ◽  
Yield Potential ◽  
Soil P ◽  
Mycorrhizal Associations ◽  
Mycorrhizal Association ◽  
Mycorrhizal Development ◽  
P Supply

Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may improve P nutrition and crop yield potential. Alternately, under low-P conditions, encouragement of arbuscular mycorrhizal associations may enhance P uptake by crops early in the growing season, improving crop yield potential and replacing starter fertilizer P applications. Soil P supply that exceeds P requirements of the crop may preclude mycorrhizal development. To encourage arbuscular mycorrhizal association, threshold levels of soil solution P that restrict mycorrhizal development must not be exceeded. Sustainable P management practices must be applied both in conventional and in alternative biologically based agricultural systems. Key words: Microbiology, fertility, colonization

scholarly journals Maturity at harvest and postharvest quality of summer squash

2019 ◽  
Vol 54 ◽  
Author(s):  
Juan Facundo Massolo ◽  
Juan Manuel Zarauza ◽  
Joaquín Héctor Hasperué ◽  
Luis María Rodoni ◽  
Ariel Roberto Vicente
Keyword(s):  
Phenolic Compounds ◽  
Developmental Stages ◽  
Sugar Content ◽  
Chilling Injury ◽  
Postharvest Quality ◽  
Cucurbita Maxima ◽  
Summer Squash ◽  
Increasing Trend ◽  
Postharvest Life

Abstract: The objective of this work was to evaluate the influence of harvest at maturity on the composition, quality, and postharvest life of zapallito squash (Cucurbita maxima var. zapallito). Fruit were harvested at three developmental stages - small, medium, and large, with 30, 70, and 90±10-mm diameter, respectively - and were stored at 0 and 5°C for 26 days and, then, at 20°C for 2 days. The following parameters were determined: respiration, firmness, color, chlorophyll content, carotenoids, sugars, acidity, phenolic compounds, antioxidants, decay, mass loss, and chilling injury (CI). Small light-colored squashes were more prone to dehydration and decay. Delaying harvest markedly reduced fruit carotenoid contents, acidity, and respiration rate; however, it did not affect firmness nor sugar content. Chlorophyll showed an increasing trend during fruit development. Small squashes had 100% higher levels of phenolic compounds and antioxidants than medium and large fruit, but were more sensitive to CI. No differences for CI susceptibility were observed between medium and large fruit. The quality of small, medium, and large squashes remained acceptable for 12, 19, and 26 days at 5ºC, respectively, plus 2 days at 20ºC.

Aggregation of sand-dune soil by endomycorrhizal fungi

1976 ◽  
Vol 54 (3-4) ◽  
pp. 326-333 ◽  
Author(s):  
J. C. Sutton ◽  
B. R. Sheppard
Keyword(s):  
Sand Dune ◽  
Mycorrhizal Fungus ◽  
Soil Extract ◽  
Dominant Factor ◽  
Phaseolus Vulgaris L ◽  
Major Mechanism ◽  
Mycorrhizal Roots ◽  
Sand Particles ◽  
Mycorrhizal Development ◽  
Dune Soil

The mycorrhizal fungus Glomus in association with bean hosts (Phaseolus vulgaris L.) was the dominant factor in the aggregation of sand particles in sterilized dune soil artificially inoculated either with Glomus, or with Glomus and a soil extract containing miscellaneous microorganisms. The weight of sand adhered to roots harvested from dried soil was about 3 times greater in mycorrhizal than in nonmycorrhizal roots. The weight of sand aggregates per kilogram dried soil from among roots of senescent beans was 10 g in nonmycorrhizal plants but 54 g in mycorrhizal plants. The fungitoxicant benomyl prevented mycorrhizal development and markedly restricted sand aggregation on and among roots of beans grown in soil inoculated with Glomus. A soil extract enhanced mycorrhizal development, the amount of sand adhered to mycorrhizal roots, and the extent of sand aggregation among mycorrhizal roots. Based on microscopic observations, the major mechanism linking sand grains in aggregates was the binding of sand to extensive Glomus mycelia.

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