Range Of Leaf Sizes Research Articles

Лесная растительность северо-западной части Малого Кавказа

Life forms, a range of leaf sizes, ethnobotany and a description of the floristic features of plants common in the North-Western forests of the Lesser Caucasus are presented in the paper. The studies were carried out in 2018–2020 on the territory of the forests of the Dashkesan and Goygol districts of the Azerbaijan Republic, which are part of the Lesser Caucasus, biodiversity was studied and the population was interviewed using generally accepted methods. Data about various life forms of local plants and their leaf size spectra are presented. 125 plant species belonging to 40 families have been identified, of which the Rosaceae family (48 species) and Poaceae (20 species) are predominant. Some plants are used to make medicines, food, feed, fuel, furniture, and housing as shown results. For this reason, forests are used in an integrated manner and vegetation is rapidly declining due to deforestation. The data for the protection of the rich vegetation in this area was taken from primary sources. The terrestrial flora is dominated by megaphanerophytes, followed by therophytes. Hemicryptophytes, nanophanerophytes and geophytes are less common in local forests respectively. The vegetation cover is formed depending on the availability of trees. Microphylls and megaphylls dominate in the spectra of leaf sizes.

Structured Light-Based 3D Reconstruction System for Plants.

Camera-based 3D reconstruction of physical objects is one of the most popular computer vision trends in recent years. Many systems have been built to model different real-world subjects, but there is lack of a completely robust system for plants.This paper presents a full 3D reconstruction system that incorporates both hardware structures (including the proposed structured light system to enhance textures on object surfaces) and software algorithms (including the proposed 3D point cloud registration and plant feature measurement). This paper demonstrates the ability to produce 3D models of whole plants created from multiple pairs of stereo images taken at different viewing angles, without the need to destructively cut away any parts of a plant. The ability to accurately predict phenotyping features, such as the number of leaves, plant height, leaf size and internode distances, is also demonstrated. Experimental results show that, for plants having a range of leaf sizes and a distance between leaves appropriate for the hardware design, the algorithms successfully predict phenotyping features in the target crops, with a recall of 0.97 and a precision of 0.89 for leaf detection and less than a 13-mm error for plant size, leaf size and internode distance.

Effects of environmental stress on leaf hair density and consequences for selection

Abstract We explored how five different environmental stresses and a benign environment affect the phenotypic expression of leaf hairs, and the potential for evolutionary response in this trait. To address these questions we planted full-sib families that had been selected for stress tolerance in a factorial design in which selection history was fully crossed with the current environment (eight families × six selection histories × six current environments × three blocks=864 plants). Our data suggest that leaf hair density is a complex character composed of two separable traits: leaf area and the number of hairs initiated per leaf. Leaf size is primarily controlled by the growth environment, whereas leaf hair initiation shows more genetically based variation. In the control and low water environments there was a negative linear relationship between leaf size and leaf hair density. However, within the low light and high boron treatments, leaf hair density remained constant across a range of leaf sizes, suggesting that these stresses disrupt normal leaf hair development. Selection gradient analysis showed that leaf hair density and leaf size were significantly positively associated with fitness in 4/6 of our environments. Our results suggest that environmental variation may diminish the ability of herbivores and pathogens to cause directional selection on leaf hair density.

Evaluation of seed production potential in white clover (Trifolium repens L. varietal improvement programmes

AbstractThe components of actual and potential seed yield were examined in field experiments on a wide range of varieties of white clover (Trifolium repens L.). The factors affecting seed yield under conditions typical of management regimes used in the production of commercial seed crops were assessed in two experiments. In the first, carried out on spaced plants, considerable diferences are shown between six varieties across the range of leaf sizes in the distribution and profuseness of inflorescence production through the flowering season. In the second, carried out in plots, typical on‐farm criteria were used to choose a single harvest date. Significant variation was found between varieties, including representatives of different leaf size categories, for seed yield components that include number of inflorescences m−2, number of florets per inflorescence and harvestable seed weight. Large‐leaved varieties tended to produce more seeds per floret and higher seed weights per inflorescence, whereas small‐leaved varieties gave the highest number of inflorescences −2. However, the small‐leaved variety AderDale, selected for strong peduncles, was exceptional, giving high values for all seed yield components. The impact of weather conditions on many seed yield components (e.g. total number of inflorescences) was demonstrated by the differences between the 2 years of the experiment. However, other characterstics, e.g. number of florets per inflorescence and number of seeds per floret, did not vary between years. Deviations from potential seed yield were assessed fromthe perspective of commerical seed production. The implications of these results for the production of white clover varieties with increased seed yields under UK conditions are discussed.

Techniques for Collecting Aquatic and Marsh Plants

Aquatic and marsh plants are those species occurring in substrates saturated with water most or all of the year. These substrates may be inundated permanently or may have the water table at the substrate surface. This habitat often poses a barrier to the collector and special problems in specimen preparation. As a result, aquatic and marsh plants are often inadequately collected and, therefore, poorly represented in herbaria. When collecting for aquatic or marsh species, I examine almost every wet spot, pool, lake, or stream I encounter and wade to the plants, if necessary. The substrate is often quite muddy and I may sink to the knees or deeper. When the water is too deep to wade, I prefer using a small boat and then dragging the substrate with a rake or grappling hook (one constructed from pipe ca. 20 cm long by 2 cm wide, coat-hanger, and rope ca. 10 m long is adequate). One can, of course, stand on shore and toss the grappling hook into the bed of plants, if the plants are fairly close. It is important to make complete specimens, including stems, leaves, roots, and reproductive structures-preferably mature flowers and fruits-of aquatic and marsh plants. Both staminate and carpellate flowers should be collected for taxa with imperfect flowers, e.g., Hydrocharitaceae.. Sterile specimens should be collected only for those taxa, e.g., Lemnaceae, that are so rarely seen in flower that the taxonomy is based upon vegetative features. Some persons believe that aquatic habitats are visited so rarely that it is better to collect a sterile specimen than none at all. However, if the specimen cannot be determined, it might as well be left in nature. Label data are especially important with aquatic or marsh plants. Information other than normal locality data that should be included are depth of water; flow rate of water; range of leaf size; whether leaves are submersed, floating, or emergent; color of flower; odor of flower; time of day of flowering; whether flowers are submersed, floating, or emergent; and whether fruits are submersed, floating, or emergent. Care must be taken to prepare quality specimens of aquatic vascular plants. They normally do not need to be pressed immediately following collection. I usually wrap each collection in dry newspaper and store these wrapped collections in plastic bags or styrofoam chests. These bags or chests are kept in the shade to prevent overheating the plants. The moisture from the specimens is adequate to moisten the newspaper and to keep the specimens fresh and pliable for several hours. The plants can be pressed later that day when one has ample time to do the task carefully. Several taxa, e.g., Heteranthera and Utricularia, have delicate flowers that are destroyed or from which the corolla falls offin the bag or press. Two or three flowers of these taxa should be preserved in 50% aqueous methyl or ethyl alcohol solution. Plastic 20 ml vials are excellent for this. Also, the duckweed press, which is discussed later, works well for pressing these flowers. Many species of aquatic and marsh plants have fairly large bulky stems, leaves, and subterranean parts. These large organs pose special problems when pressing. First, all parts of a specimen, other than the bulky structures, will have inadequate pressure in the press; as a result, they shrink during the drying process. This shrinking can be corrected by placing layers of newspaper on the flatter parts while the plant is in the press. Second, these bulky organs tend to have large amounts of water and, therefore, dry slowly-so slowly, in fact, they may completely decay while in the press. This decaying can be eliminated by splitting the large structures before pressing and by changing the corrugates and blotters of the press each day. Delicate aquatic plants, especially those that

Area Measurement of Mesquite (Prosopis glandulosa) Leaves by Using Leaf- Length Measurements

In mesquite, Prosopis glandulosa var. glandulosa (Torr.) Cockr., which has a doubly pinnate leaf, a log-log relationship was found to exist between the sum of the lengths of the rachises of each leaf and the total surface area of the leaf. Regression analysis using complete and incomplete leaves from small and large trees indicates that the log of the sum of the lengths of the rachises and the log of the total leaf area produced a linear correlation coefficient of .96. The relationship holds for complete and incomplete leaves and for a large range of leaf sizes from a variety of growing conditions.