Beginning Of Branching Research Articles

Effect of spraying with different concentrations of the growth regulator paclobutrazol on the yield characteristics of three varieties of oat crop Avena sativa L.

The experiment was conducted at the Research Station of the College of Agriculture, University of Basrah,located north of Basrah city, during the winter season of 2022-2023, in a loamy soil. The study aimed toinvestigate the response of three varieties of oats (Avena sativa L.) to foliar spraying with differentconcentrations of the growth regulator paclobutrazol. The study included three oat varieties (Ganzania,Shafa, and CarlIoup) under the influence of spraying three concentrations of paclobutrazol (25, 50, and100 mg/L) and a control treatment. The interaction between the two factors was also studied. Thespraying was carried out in two stages, the first at the beginning of branching, and the second after threeweeks from the first spray.The experiment was arranged using a randomized complete block design(RCBD) with three replicates. The results showed the superiority of the paclobutrazol treatment (50 mg.l-1), which recorded the highest averages for most of the studied yield characteristics, as the lowestaverage number of panicles m-2was recorded at 458.05 dalia - and the highest average number of grainsper dalia was 55.45 grains g-1, and the highest average weight was recorded. 1000 grains amounted to37.33 g, while the Ganzania variety was superior in terms of the number of days and the number ofgrains in of panicl and 1000 grains amounted to 458.05 and amounted to 55.45 grains in of panicl-1 and 34.93 g and its components, protein content in grains, and chlorophyll in leaves were studied. Theresults showed the superiority of the paclobutrazol treatment (50 mg/L), which recorded the highestmeans for most of the studied growth traits. It had the lowest average plant height, reaching 70.75 cm. Italso recorded the highest average chlorophyll content, reaching 143.90 mg/100 g, and the highest averagefor the number of tillers, reaching 488.97 tillers/m². Additionally, it recorded the highest average for stemdiameter, reaching 4.49 mm.

The roles of interspecific variability in seed mass and soil resource availability in root system development

Because plant roots serve mainly as organs for the uptake of water and nutrients, we aimed to test whether the development of seedling roots is influenced by the two principal nutrient sources—the substrate and the pool stored in the seed itself. Using seven Fabaceae species that differ in seed mass, we observed their early root system development under four levels of nutrient availability. Transparent-wall rhizoboxes allowed us to track root development and to score root system structure (length and number of roots), size (depth and width of root system) and shape (relative depth and width of root system). Seedling root system development depended on both the amount of nutrients contained in the substrate and on the seed mass of the species. Compared to an average seedling, effects of these two nutrient pools were (i) opposite and (ii) did not fully overlap. Small-seeded species developed wider root systems that branched earlier than large-seeded species. Increased availability of nutrients in the substrate led to proliferation of lateral roots, without any substantial impacts on the shape of root system or beginning of branching. The source of the nutrients affected the way they were used throughout early root system development, leading to different structures and dynamics. This may be one of the mechanistic links connecting seed mass and the realized niche of the species.

Radiocarbon Dating of an Olive Tree Cross-Section: New Insights on Growth Patterns and Implications for Age Estimation of Olive Trees.

The age of living massive olive trees is often assumed to be between hundreds and even thousands of years. These estimations are usually based on the girth of the trunk and an extrapolation based on a theoretical annual growth rate. It is difficult to objectively verify these claims, as a monumental tree may not be cut down for analysis of its cross-section. In addition, the inner and oldest part of the trunk in olive trees usually rots, precluding the possibility of carting out radiocarbon analysis of material from the first years of life of the tree. In this work we present a cross-section of an olive tree, previously estimated to be hundreds of years old, which was cut down post-mortem in 2013. The cross-section was radiocarbon dated at numerous points following the natural growth pattern, which was made possible to observe by viewing the entire cross-section. Annual growth rate values were calculated and compared between different radii. The cross-section also revealed a nearly independent segment of growth, which would clearly offset any estimations based solely on girth calculations. Multiple piths were identified, indicating the beginning of branching within the trunk. Different radii were found to have comparable growth rates, resulting in similar estimates dating the piths to the 19th century. The estimated age of the piths represent a terminus ante quem for the age of the tree, as these are piths of separate branches. However, the tree is likely not many years older than the dated piths, and certainly not centuries older. The oldest radiocarbon-datable material in this cross-section was less than 200 years old, which is in agreement with most other radiocarbon dates of internal wood from living olive trees, rarely older than 300 years.

Effect of sowing date in growth characteristics for several cultivars of sesame (Sesamum indicum L.)

A field experiment has been fulfilled in sandy - clay texture soil in Al-Jazira region in Al-Khalidia town in Al-Anbar province during summer season of 2000 ac. To study the effect of sowing dates (1st may, 15th may, 1st June and 15th June) in growth characteristics of four cultivars from sesame (Al-Mahali, Ishtar, Babel and Rafadeen) and determine the best cultivar and date of sowing given the best growth for sesame under the climate of Al-Anbar governorate. The factorial experiment has been used according to random complete block design (R.C.B.D.) with three replicate. The following were obtained results: The cultivars different significantly in growth characters, the derivative cultivars especially Ishtar are earlier in duration (period) of maturity (ripening) and mean 15.64 day compared with Al-mahali cultivar whose overcame on them in stem diameter (1.36 cm), number of branches per plant (4.10 branch) dry weight of plant (16.83 g / plant). while Ishtar and Babel are overcame in shortest of stem height from ground (earth) until the beginning of branching (12.54 , 13.12) cm. The last cultivar also overcame in high mean of plant height (149.13 cm) as compared with other varieties. There was a significant effect for sowing dates in most growth characters. The plants which are planted at 1st may recorded a high mean for dry weight of plant (15 g / plant) and number of day from sowing to ripening (150.82 day) compared which are planted in 15th June which earlier in ripening (110 day) and overcame in stem diameter (1.27 cm), while the plants are sowing in 1st June recorded a high mean of plant height (153.35 cm). the dates of sowing not effect significantly in the stem long from earth surface until beginning of branching and number of branches / plant. The interaction between sowing dates and cultivars had significant effect in all growth characters except number of branch / plant. The local cultivar that sowing in 1st June gave a highest mean of plant height (182.15 cm), stem diameter (1.58 cm) and plant dry weight (27.75 g / plant). The Ishtar cultivar that sowing in the same date also recorded a less distance to beginning of branches (9.83 cm) and earlier in ripening when sowing in 15st June (104.66 day) as compared with other treatments especially with local cultivar that planting in 1st may (164.66 day).

Effect of sowing date in growth characteristics for several cultivars of sesame (Sesamum indicum L.)

A field experiment has been fulfilled in sandy - clay texture soil in Al-Jazira region in Al-Khalidia town in Al-Anbar province during summer season of 2000 ac. To study the effect of sowing dates (1st may, 15th may, 1st June and 15th June) in growth characteristics of four cultivars from sesame (Al-Mahali, Ishtar, Babel and Rafadeen) and determine the best cultivar and date of sowing given the best growth for sesame under the climate of Al-Anbar governorate. The factorial experiment has been used according to random complete block design (R.C.B.D.) with three replicate. The following were obtained results: The cultivars different significantly in growth characters, the derivative cultivars especially Ishtar are earlier in duration (period) of maturity (ripening) and mean 15.64 day compared with Al-mahali cultivar whose overcame on them in stem diameter (1.36 cm), number of branches per plant (4.10 branch) dry weight of plant (16.83 g / plant). while Ishtar and Babel are overcame in shortest of stem height from ground (earth) until the beginning of branching (12.54 , 13.12) cm. The last cultivar also overcame in high mean of plant height (149.13 cm) as compared with other varieties. There was a significant effect for sowing dates in most growth characters. The plants which are planted at 1st may recorded a high mean for dry weight of plant (15 g / plant) and number of day from sowing to ripening (150.82 day) compared which are planted in 15th June which earlier in ripening (110 day) and overcame in stem diameter (1.27 cm), while the plants are sowing in 1st June recorded a high mean of plant height (153.35 cm). the dates of sowing not effect significantly in the stem long from earth surface until beginning of branching and number of branches / plant. The interaction between sowing dates and cultivars had significant effect in all growth characters except number of branch / plant. The local cultivar that sowing in 1st June gave a highest mean of plant height (182.15 cm), stem diameter (1.58 cm) and plant dry weight (27.75 g / plant). The Ishtar cultivar that sowing in the same date also recorded a less distance to beginning of branches (9.83 cm) and earlier in ripening when sowing in 15st June (104.66 day) as compared with other treatments especially with local cultivar that planting in 1st may (164.66 day).

Scanning electron microscopic observation of mouse embryonic submandibular glands during initial branching: preferential localization of fibrillar structures at the mesenchymal ridges participating in cleft formation

Branching submandibular glands of 12-day mouse embryos and those cultured in the presence and absence of a collagenase inhibitor from the culture medium of bovine dental pulp or a Clostridial collagenase were examined with the scanning electron microscope. Fracturing of fixed and dried glands with the tip of a fine needle succeeded in exposing the surfaces of the lobules and of their mesenchymal replicas at different stages of branching. At the beginning of branching, corresponding parts of the mesenchyme formed ridges on or in which the fibrillar structures were often found. At the stage forming deeper clefts thicker fibres, 0.5-2.5 micron in diameter, were observed between two adjacent lobules. On the contrary, no apparent differences in the fibrillar structures on the epithelial surfaces were detected between the shallow cleft and noncleft regions at the initial phase of branching. These fibrillar structures were very abundant in glands cultured with collagenase inhibitor and were completely lost in glands cultured with bacterial collagenase, strongly indicating that these materials consisted of collagen. The possible involvement of mesenchyme in epithelial branching is discussed with special reference to mesenchymal traction forces that would be elicited by fibrillar collagens.

Observations on the sporulation of cucumber downy mildew fungus.

Sporulation process of cucumber downy mildew fungus (Pseudoperonospora cubensis) was studied, and microphotographed by use of the methods adopted by Toyoda and Suzuki (1952) for rice blast fungus.The diseased leaf was detached at 7.00-8.00 p.m. from the potted cucumber plants grown in the greenhouse, and its surface was washed with water to remove the existing conidiophores. The lesion was then cut off into a piece of 1×2cm. and placed in a moist cell under a microscope in a dark room, at 22-26°C. for periodical observation.After the leaf lesion was placed in the moist cell, conidiophores emerged through the stomata from 2 to 4 1/2 hours, and began to branch dichotomously from 6 1/2 to 9 hours. They continued to branch in the same manner until they had 3 to 16 ultimate branchlets. 20 to 50 minutes after the beginning of branching, a small hyaline projection was produced almost simultaneously at each ultimate branchlet of a conidiophore. This projection developed, to a mature conidium 50 to 70 minutes later, turning grey.When the conidiophore which had begun to branch was subjected to unfavorable conditions such as drying, it stopped to branch and turned to produce conidia.