Anatomical, morphological and growth responses of Thinopyrum ponticum plants subjected to partial and complete submergence during early stages of development

2020 ◽  
Vol 47 (8) ◽  
pp. 757
Author(s):  
María del Rosario M. Iturralde Elortegui ◽  
Germán D. Berone ◽  
Gustavo G. Striker ◽  
María J. Martinefsky ◽  
María G. Monterubbianesi ◽  
...  

Seedling recruitment and growth of forage grasses in flood-prone grasslands is often impaired by submergence. We evaluate the responses of Thinopyrum ponticum (Podp.) Barkw. & Dewey to partial and complete submergence at two early stages of development. Two greenhouse experiments were carried out with plants at three expanded leaves (Experiment 1) or five expanded leaves stage (Experiment 2). In each case, three treatments were applied for 14 days: control (C), partial submergence (PS; water level to half plant height), and complete submergence (CS; water level to 1.5 times plant height). Submergence was followed by a recovery period of 14 days at well drained conditions. Assessments included plant survival, height, leaf blade and pseudostem length, soluble carbohydrates in pseudostem, and shoot and root dry mass accumulation at the beginning and end of the submergence, and at the end of the recovery period. Root aerenchyma formation was determined on day 14 in both experiments. Under PS all plants survived, and the impact of the stress was related to the plants’ developmental stage. However, plants with five expanded leaves increased total plant biomass with respect to control by 48%, plants with three expanded leaves reduced it by the same percentage. This response could be related to a higher ability to form root aerenchyma (17 vs 10%), and an enhanced leaf de-submergence capacity due to promoted leaf blade and pseudostem lengthening. Complete submergence treatment compromised the survival of 70% of the individuals with three expanded leaves but did not affect the survival at the five expanded leaves stage. In any developmental stage (three or five expanded leaves) plants fail to promote enough elongation of leaf blades or pseudostems to emerge from the water, so that always remained below the water surface. Root aerenchyma was not increased by CS at either of these two plant developmental stages. The high amount and concentration of pseudostem total soluble carbohydrates of the larger (five expanded leaves) plants facilitated their recovery growth after submergence. Our results predict the successful introduction of this species in areas where water excesses can cause soil waterlogging or shallow-partial plant submergence, but suggest avoidance of areas prone to suffer high-intensity flooding that lead to full plant submergence as this would highly constrain plant recruitment.

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 135-148
Author(s):  
J. Vasse

Experimental study on the early stages of development of the front limbs of the embryo of the chelonian Emys orbicularis L.: mosaic determination and regulation Ablation of postotic somites 6–13 on one side in embryos of Emys orbicularis L. or injury to the adjacent somatopleure at the developmental stage when 15–21 somite pairs were present, led to arrest of forelimb-bud development in this part of the somatopleure on the operated side. Limb development in the remaining part of prospective somatopleure on the operated side was investigated 5–11 days after the operation. When this part of somatopleure was adjacent to cranial somites 6–9 or 6–10, the development stopped at the start of the apical crest as in Anguis or Scelotes forelimb-buds. A part of somatopleure adjacent to caudal somites 8–12, 9–12 or 10–12 developed into a normal limb with three segments; a part of somatopleure adjacent to 1–2 somites only, developed into a reduced limb, scarcely swelling. Each somitic level developed in relation to its initial regional determination dependent on position in the cephalocaudal axis; to its environment (cranial or caudal bud) and to the quantity of somatopleural material in the bud.


Development ◽  
1974 ◽  
Vol 32 (2) ◽  
pp. 417-430
Author(s):  
Par J. Vasse

Experimental study on the role of the somites during the early stages of development of the front limbs of the embryo of the chelonian Emys orbicularis L. Ablation of postotic somites 6–13 on one side in embryos of Emys orbicularis L. at the developmental stage when 20–23 somite pairs were present, led to arrest of forelimb-bud development in the somatopleure adjacent to the ablated somites on the operated side. Limb development in the somatopleure adjacent to intact somites on the operated side was unaffected, attaining the same stage as on the non-operated side. Ablation at later stages (25–33 somite pairs) did not prevent development of the limb adjacent to the ablated somites. When a part of the prospective somatopleure was injured, the remaining part formed a small limb-bud. When an obstacle was placed between the somatopleural mesoderm and the adjacent somite, development of the somatopleure stopped at this level. These results corroborate those obtained from previous studies in various reptilian embryos concerning the role of the ventral somite extensions as activators of proliferation in the somatopleural mesoderm. Injury to the ventral extension alone led to serious disturbances in the somatopleural mesoderm adjacent to this somite.


2016 ◽  
Vol 9 (3) ◽  
pp. 193-196
Author(s):  
Eires Tosta Fernandes ◽  
Crébio José Ávila

A soja, Glycine max (L.), é uma cultura que pode ser prejudicada por insetos-praga durante todo o ciclo fenológico, principalmente nos estádios iniciais  desta cultura. O objetivo deste trabalho foi avaliar a resposta da cultura da soja a diferentes tipos de injúrias artificiais causadas nos seus estádios iniciais de desenvolvimento. O experimento foi conduzido na área experimental da Embrapa Agropecuária Oeste, utilizando-se as cultivares FTS Campo Mourão e BRS Potência, as quais foram submetidas aos seguintes tipos de injúrias iniciais: 1) Remoção de um cotilédone; 2) Remoção de dois cotilédones; 3) Remoção de dois cotilédones e uma folha unifoliolada; 4) Remoção de dois cotilédones e duas folhas unifolioladas; 5) Remoção de uma folha unifoliada; 6) Remoção de duas folhas unifolioladas; 7) Corte abaixo das folhas unifolioladas; 8) Corte do broto trifoliado; 9) Testemunha (sem injúria). A altura das plantas, o número de vagens/planta e o peso verde da parte aérea da cultivar FTS Campo Mourão foram menores quando comparado com os valores desses parâmetros obtidos na cultivar BRS Potência. Foi também constatado redução na altura das plantas de soja nos tratamentos 3, 4, 6 e 7 quando comparado à testemunha. O rendimento de grãos (Kg ha-1) foi semelhante nas duas cultivares e não foi influenciado pelos diferentes tipos de injúrias causados nas plantas. Já o peso de 100 sementes (g) foi maior na cultivar FTS Campo Mourão quando comparado a cultivar BRS Potência. Independente dos tipos de injúrias que são causadas, as plantas apresentam capacidade de recuperação ao dano.Effect of Different Types of Injury Caused During the Early Soybean Development Stages Abstract. The soybean, Glycine max (L.), is a crop that can be damaged by insect pests throughout its phonological cycle, particularly in the early stages of development of this culture. The aim of this study was to evaluate the response of soybean to different types of artificial injuries caused in its early stages of development. The experiments were carried out at Embrapa Agropecuária Oeste using the cultivars FTS Campo Mourão and BRS Potência. These cultivars were submitted to nine treatments of artificial injuries, as follow: 1) removal of one cotyledon; 2) removal of two cotyledons; 3) removal of two cotyledons and one unifoliate leaf; 4) removal of two cotyledons and two unifoliate leaves; 5) removal of one unifoliate leaf, 6) removal of two unifoliate leaves; 7) cut below the unifoliate leaves; 8) cut below the trifoliate bud; 9) untreated (without injury). The plant height, the number of pods/plant and fresh weight of aerial part in Campo Mourão cultivar were lower than that observed with the Potência cultivar. There was also reduction of the plant height in the treatments 3, 4, 6 and 7 when compared to the control (without injury). The grain yield (Kg ha-1) was similar in both cultivars and was not influenced by the different types of injuries applied in plants of both cultivars. The weight of 100 seeds (g) was higher in cultivar Campo Mourão when compared to Potência cultivar. Regardless of the types of injuries that are caused, the plants have resilience to damage.


2017 ◽  
Vol 59 (2) ◽  
pp. 053-063
Author(s):  
Anna V. Pirog ◽  
◽  
Olga V. Lozhnichenko ◽  

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.


1878 ◽  
Vol 169 ◽  
pp. 505-521 ◽  

The following paper contains an account of observations on the development of the species Cymothoa œstroides and C . parallela of Milne Edwards; but the forms of the young seem to show that several species are really included under these two names. In the early stages of development the only observable difference that exists between the embryos is one of size, but in the later stages they differ very markedly from each other in their external characters. From adult individuals answering the description of C . œstroides I have obtained four varieties of embryos: two with long antennae and two with short.* In the two former the first pair of antennae are but slightly longer than the head, while the second pair are longer than the body; the eyes are small. In one of the varieties thus characterised the abdominal appendages are fringed with long hairs (fig. 20), and in the other they are smooth.


Zootaxa ◽  
2021 ◽  
Vol 4995 (3) ◽  
pp. 594-600
Author(s):  
MARCO VIOLANTE-HUERTA ◽  
LAURA SANVICENTE-AÑORVE ◽  
MARGARITA HERMOSO-SALAZAR ◽  
AURORA MARRÓN-BECERRA

Lack of knowledge of morphological variations during growth of amphipod crustaceans can result in misidentification of species. In this study, we advance the knowledge of morphological variations of juveniles of the monotypic genus Phrosina Risso, 1822 collected in the oceanic province of the southern Gulf of Mexico. The juveniles differed from the adults mainly in the morphology of pereopods 3 & 4 in that the carpal process is parallel to the propodus, also the rami of the pleopoda consist of only four segments, uropoda 3 are more lanceolate, and the uropoda bear a large prominent spine terminally. These morphological variations have not been described for the species previously. Therefore, the current observations enrich the description of P. semilunata in the early stages of growth and support the need for further taxonomical studiest that could help identify species at different stages of development.  


2021 ◽  
Vol 13 (2) ◽  
pp. 132-137
Author(s):  
Elizabeth Coombes ◽  
Marion Musting ◽  
 Ivad Al-Muzzafar ◽  
Christina Kalliodi 

There is a growing body of music therapy work addressing the needs of infants born prematurely. This also includes work with parents and other family members during hospitalisation. A variety of music therapy interventions are utilised to support a range of treatment goals for this client population. This report describes and discusses such work that is in the early stages of development in 3 European countries: Estonia, Greece and Wales. The development and content of the interventions in each country is described, with recommendations as to the sustainability and future growth of each programme


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