Targeted CRISPR/Cas9-Based Knock-Out of the Rice Orthologs TILLER ANGLE CONTROL 1 (TAC1) in Poplar Induces Erect Leaf Habit and Shoot Growth

Pyramidal-, erect- or upright-growing plant forms are characterized by narrow branch angles of shoots and leaves. The putative advantage of upright-leaf and shoot habit could be a more efficient penetration of light into lower canopy layers. Pyramidal genotypes have already been reported for various tree genotypes including peach. The paralogous rice ortholog TILLER ANGLE CONTROL 1 (TAC1) has been proposed to be the responsible gene for upright growth. However, it has not really been demonstrated for any of the pyramidal tree genotypes that a knock-out mutation of the TAC1 gene is causing pyramidal plant growth. By in silico analyses, we have identified a putative rice TAC1 ortholog (Potri.014G102600, “TAC-14”) and its paralog (Potri.002G175300, “TAC-2”) in the genome of P. trichocarpa. Two putative PcTAC1 orthologs in the P. × canescens clone INRA 717-1B4 were successfully knocked-out by applying a transgenic CRISPR/Cas9-approach. The mutants were molecularly analyzed and phenotyped over a period of three years in a glasshouse. Our results indicate that the homozygous knock-out of “TAC-14” is sufficient to induce pyramidal plant growth in P. × canescens. If up to twice as many pyramidal individuals were planted on short rotation coppices (SRCs), this could lead to higher wood yield, without any breeding, simply by increasing the number of trees on a default field size.

Carbon Sequestration by the Standing Mangrove Trees at the Achara Estuary along the Coast of Maharashtra State (India)

Mangroves or all the plants are known to absorb the atmospheric carbon by photosynthesis. This absorbed carbon is stored in various organic forms and helps to produce the biomass. Trees dominate this process. Greater and taller is the size of the tree more is the amount of carbon fixed. Hence trees are the major plant forms to absorb maximum atmospheric carbon and biomass production. Thus, the present investigation was carried out to calculate the carbon sequestration of 12 standing mangrove tree species in Achara estuary of Sindhudurg district of Maharashtra state. The biomass and total organic carbon of standing trees is estimated by the non-destructive method. The population of Avicennia marina var. acutissima Staf. & Mold. and Rhizophora mucronata Lamk. are more in the estuary and they sequestrate about 585.70×106 and 375.10×106 lbs carbon respectively. A total of 1892.96×106 lbs of the carbon is sequestering by all the mangrove trees present in the estuary.

Unusual Order of Chromosome Arrangement Location in Late Prophase - Early Prometaphase of Mitosis in Haploid Maize Plant Obtained With the Use of Mutation ig

Despite the huge amount of works devoted to the study of mitotic division, there is still a lot of unclear in its mechanisms. For example, insufficient attention has been paid to the processes of cell division in plant forms of different ploidy levels. The literature contains only fragmentary data on haploids in lower plants. This does not allow making any generalizations regarding mitosis in haploids of higher plants. This article presents the results of a cytological study of mitotically dividing cells of haploid maize plants. The article demonstrates the effectiveness of the well-known Chase method, based on the use of genetic markers and the ig mutation (indeterminate gametophyte) for obtaining and detecting haploids. An effective modification of a simple method of acetocarmine staining of cytological preparations is described. An essential result obtained is, in our opinion, the detection of a very brief moment in the state of chromosomes in a dividing cell of a haploid maize plant. This moment is characterized by the fact that the chromatids have already separated and turned into independent chromosomes, but have not yet begun their movement under the action of kinetochore microtubules. It is this feature that made it possible to designate this state as late prophase – early prometaphase of mitosis. An equally important feature of the detected moment is the unusual ordered arrangement of chromosomes, which lie parallel to each other close to each other along their entire length with the centromeres located on one line, which can be considered the equator of the fission spindle. The revealed fact allows us to assume that an essential role in the formation of such an arrangement of chromosomes is played by the bond of chromosomes with the equator of the nuclear membrane and their subsequent connection with the equator of the fission spindle.

Evaluation of lambda-cyhalothrin oxidative stress and gonad histoarchitecture toxicity potency in Clarias gariepinus

Background Extensive and indiscriminate use of pesticides gradually destroys the environment (ecosystem), poses serious threats to human health, animal life (especially aquatic), plant forms, soil, water, and also lead to emergence of resilient species of life forms that are becoming resistant to pesticides. The present study focused on evaluating lambda-cyhalothrin oxidative stress and gonad histoarchitecture toxicity potency in Clarias gariepinus. Results A total of 120 C. gariepinus 16 to 40 cm SL and 200 to 250 g bodyweights (assigned into treatments 0.00 (control), 2.5 × 10−4 μg/L, 5.0 × 10−4 μg/L, and 6.25×10−4 μg/L (A-D) lambda-cyhalothrin (LCT), each treatment consisted of 30 fishes, replicated three times, 10 fishes per replicate) were used for this study. On day 7, catalase activity (CAT) and glutathione peroxidase (GPx) significantly increased (p < 0.05) in all treatments compared with control. Day 14, superoxide dismutase (SOD) and GPx significantly increased (p < 0.05). All parameters significantly increased (p < 0.05) on days 21 and 28 except SOD (day 21). All parameters increased significantly on day 28 across the row in all treatments. The significant increase (p < 0.05) in SOD, (malondialdehyde) MDA, GPx, and glutathione reductase (GR) levels returned to normal after 7 days of depuration but CAT level did not return to normal. The testes photomicrographs showed necrotic conditions in the spermatogenic cells with nuclear pyknosis and cytoplasmic swelling while that of the ovary displayed vacuolations, flabby oocytes, and degenerated ovaries changes. Conclusion Lambda-cyhalothrin is toxic to C. gariepinus. The inability of significant increase in CAT to return to normal after 7 days of depuration further confirms our report.

THE PROBLEMS OF INCREASING THE EFFICIENCY OF SORGHUM SEED PRODUCTIONIN THE ALTAI REGION AND THE SOLUTIONS

The yield potential of sorghum crops is reached through the varieties. The crops under study use atmospheric pre-cipitation very economically and efficiently; high carbohy-drate content in their herbage makes them valuable com-ponents of multi-species agrophytocenosis with high-protein crops. One of the reasons of insufficient distribution of sorghum crops is a problem of seed production. The use of seeds with low germinating ability leads to high produc-tion costs and low yields. Early ripening, mid-early and mid-ripening varieties persistently mature and produce full val-ue seeds in the Altai Region. They produce good quality seeds practically on any years regarding heat supply; their seed production causes no problem.However, they signifi- АГРОНОМИЯ28Вестник Алтайского государственного аграрного университета No8(202), 2021cantly underperform regarding forage production as com-pared to mid-late and late varieties. Large seed losses (up to 50-70%) are caused by seed cast in windy weather. The average seed cast losses in upright standing plant forms reach 48.0% while in dropping forms the losses are three times lower. The solution is the optimization of plant forms. Other approaches should be applied to seed cast problem solution. A direction of the plant breeding is the develop-ment of the varieties resistant to seed cast characterized by high seed tear-away force from panicle branches. Seed production plots of sorghum crops should be sown on ear-lier dates. Delayed sowing prevents from meeting the growing season timeline, especially of late forms. The seeding rate of 2.5 million seeds per hectare was optimum not only for seed production, but also for forage production. Special attention should be paid to the phosphorus nutrition of maternal plants. Early varieties should be harvested in two-stages; late varieties -by straight-cutting.

To R- geometry of plants

The article gives a definition of the organic form as an infinite-similar and self-similar structure, which is based on the increased unity of the whole and the part - holomereological symmetry. A model of plant forms as organic forms is proposed, which are based on spherocylinders – infinite-similar cylindrical volumes joined with hemispheres at their ends. The data on the golden wurf in the metric of plant stems are presented. The cirrus leaf model in MathCad is briefly described. The problem of the organic form, the form of living organisms, is a long-discussed topic in biology, in particular, in morphology. There is a lot of empirical material relating to the description of a huge variety of biological forms. However, until now, the laws of the organic form and its specificity, in comparison with the forms of inorganic bodies, continue to raise more questions than answers. It is clear that organic forms are special, they have their own laws and types of morphogenesis. But what is the essence of these features, what is the logic of their organization, all this is still largely unclear.

Variability of the period between germination and heading in spring barley accessions from Dagestan

Background. The genetic variability of the period between the germination and heading phases was analyzed in barley accessions from the Republic of Dagestan planted in the southern area of Dagestan (Derbent) and the Northwest of Russia (Pushkin, St. Petersburg). Testing barley development rates under contrasting climate conditions of Russia makes it possible to assess the paratypic variability and a norm of reaction in the tested accessions in order to identify environmentally adaptable plant forms useful for breeding.Materials and methods. Under spring sowing, 173 spring barley accessions were studied for the duration of the period from germination to heading. To compare the earliness of accessions planted at two sites with different sowing schedules, “the rate by which the germination-to-heading period of an accession exceeded its minimum value across the sample” was used as a criterion for calculations.Results and conclusions. Accession k-15013 was the earliest at both test sites during two years of studying. In Dagestan, accessions k-11439 and k-11475 with a low norm of reaction in 2016 and 2017 were also identified as early. Environmental conditions were found to have a significant effect on the development rate of barley accessions in Derbent and St. Petersburg. Dagestani barleys in the North-west of Russia ripened earlier than in the south of Dagestan during all the years of study. Vernalization temperatures proved to be the main factor affecting maturation schedules of local Dagestani barleys in the area of their distribution. A longer day and the absence of high temperatures in St. Petersburg contributed to the earliness of barley accessions.

The Woody Plant Species Diversity, Composition and Dominance of Mahungu Green Belt Forest Reserve (MGBFR) in Dodoma City, Central Tanzania

Plant species diversity, composition and dominance are important entities in understanding vegetation types. The wood plant species include; trees, shrubs, and woody climbers (lianas/vines). The study was conducted at Mahungu Green Belt Forest Reserve (MGBFR) in 2015 to investigate the woody plant species diversity, composition, and dominance. Systematic random sampling was applied whereby a total of 36 plots of 2500 m2 were set in the seven (7) transects at an interval of 400 m. Woody plant species were identified for their botanical nomenclature, determined for their abundance. GPS was applied to locate plots, aligning transects and recording coordinates for plot site and map production. 100 m tape was used to set the plots. H' and ID were applied for species diversity and dominance. A total of 129 wood plant species were identified belonging to 38 families and 89 genera. The H' ranged from 0.1831 ± 0.0021, with an overall total of 4.271 while ID ranged from 0.004657 ± 0.000015 with a total of 0.02079 an implication of high wood plant diversity, as the higher the H', and the lower the ID the higher the diversity. MGBFR consists of high woody plant species diversity. Further study should be done to assess all plant forms of MGBFR, education provision to community, establishment of ecotourism industry to sustain the forest reserve.