scholarly journals High temperature disturbs ovule development in field pea (Pisum sativum L.)

Botany ◽  
2021 ◽  
Author(s):  
Evelyn E. Osorio ◽  
Arthur R. Davis ◽  
Rosalind Bueckert

High temperatures affect reproductive growth and lead to yield loss in many crops. Field pea is heat sensitive, but little is known about the effect of high temperature on ovules. We investigated heat impact on ovules of flowers at various reproductive nodes of field pea using growth chambers. Six cultivars exhibiting diverse heat tolerance were exposed to four days of heat (35°C day/18°C night) during early flowering. Post-treatment ovules and embryo sacs were assessed employing clearing by light, and fluorescence, microscopy. Results indicated that greater ovule and embryo sac development occurred on some nodes, but poor ovule and embryo sac expansion resulted on other nodes of the same heat-treated plants. While advanced ovule and embryo sac development were identified on heat-tolerant cultivars, a combination of advanced and less advanced ovule and embryo sac development occurred in intermediate and heat-sensitive cultivars. More than 90% of the affected ovules displayed embryos at various stages of development, which indicated disruption around fertilization or shortly thereafter. Callose accumulation around the vascular bundle within ovules suggested disruption of assimilate transport to the embryo sac. The contrasting pattern of ovule development at different nodes implied a conflict between early aging and maternal supply of heat-treated plants.

1970 ◽  
Vol 48 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Jack Maze ◽  
Lesly R. Bohm ◽  
Lyle E. Mehlenbacher Jr.

The ovules of Stipa tortilis and Oryzopsis miliacea are hemianatropous, bitegmetic, and pseudocrassinucellate (sensu Davis 1966). The hemianatropous shape of the ovule is the result of characteristic patterns of cell division and enlargement in the chalazal area and areas alongside the embryo sac. Embryo sac development in both is Polygonum-type and both have proliferating antipodals. Endosperm is nuclear, although in O. miliacea it is atypical in that nuclear division is synchronous within one portion of the embryo sac, e.g. micropylar, but not synchronous between different portions of the embryo sac, e.g., micropylar and chalazal. Differences in ovule initiation, persistence of the outer integument, fate of the inner integument, nature of the nucellus, shape of the embryo sac, nature of the synergids, cytoplasm of the egg, polar nuclei, and endosperm exist between these two taxa. Both synergids of O. miliacea undergo changes before fertilization and one degenerates before fertilization. The pollen tube enters the embryo sac at the base of the persistent synergid. There is presently insufficient embryological data to permit meaningful speculation on relationships between Stipa and Oryzopsis. Embryologically, Stipa and Oryzopsis are festucoid grasses, as much other evidence indicates. Embryo sac development in the Gramineae is more similar to that of the Restionaceae than to that of the Cyperaceae. This is in contradiction to recent speculations on the relationships of the Gramineae.


2012 ◽  
Vol 61 (1-6) ◽  
pp. 85-93 ◽  
Author(s):  
J. Wang ◽  
X. Y. Kang ◽  
D. L. Li

AbstractTriploid breeding plays an important role in cultivar improvement in the genus Populus L. A novel approach for triploid production with colchicine during embryo sac development was reported recently by Wang et al. (2010). In the present investigation, female catkins of Populus pseudo-simonii × P. nigra ‘Zheyin3#’ during embryo sac development were exposed to high temperature to assess the effectiveness of high temperature for induction of triploid production. In the progeny, 45 triploids were determined by both flow cytometric analysis and somatic chromosome counting. The period 66-72 h after pollination was the most suitable for high temperature-induced triploid production during embryo sac development in the ‘Zheyin3#’. Cytological analysis showed that the frequency of eight-nucleate embryo sacs rose at an increased rate during 66-78 h after pollination, which suggested that the third mitosis during embryo sac development could be the optimal stage for high temperature-induced triploid production. The highest frequency of triploid production was 40%, which was obtained in the 44°C for 2 h treatment 72 h after pollination. In view of both triploid number and production efficiency, treatments with 41°C for 4-6 h or with 44°C for 2 h during 66-72 h after pollination were both effective for triploid induction in ‘Zheyin3#’. Statistical analysis showed that the growth of triploids and diploids was not significantly different. However, highly significant differences were observed for all leaf characteristics. Finally, the significance of high temperature treatment in Populus triploid breeding programs is discussed.


2020 ◽  
Vol 71 (22) ◽  
pp. 7059-7072 ◽  
Author(s):  
Maria Dolores Gomez ◽  
Daniela Barro-Trastoy ◽  
Clara Fuster-Almunia ◽  
Pablo Tornero ◽  
Jose M Alonso ◽  
...  

Abstract Ovule development is essential for plant survival, as it allows correct embryo and seed development upon fertilization. The female gametophyte is formed in the central area of the nucellus during ovule development, in a complex developmental programme that involves key regulatory genes and the plant hormones auxins and brassinosteroids. Here we provide novel evidence of the role of gibberellins (GAs) in the control of megagametogenesis and embryo sac development, via the GA-dependent degradation of RGA-LIKE1 (RGL1) in the ovule primordia. YPet-rgl1Δ17 plants, which express a dominant version of RGL1, showed reduced fertility, mainly due to altered embryo sac formation that varied from partial to total ablation. YPet-rgl1Δ17 ovules followed normal development of the megaspore mother cell, meiosis, and formation of the functional megaspore, but YPet-rgl1Δ17 plants had impaired mitotic divisions of the functional megaspore. This phenotype is RGL1-specific, as it is not observed in any other dominant mutants of the DELLA proteins. Expression analysis of YPet-rgl1Δ17 coupled to in situ localization of bioactive GAs in ovule primordia led us to propose a mechanism of GA-mediated RGL1 degradation that allows proper embryo sac development. Taken together, our data unravel a novel specific role of GAs in the control of female gametophyte development.


2018 ◽  
Vol 34 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Prachi Garg ◽  
◽  
A. Hemantaranjan ◽  
Jyostnarani Pradhan ◽  
◽  
...  

Alloy Digest ◽  
1991 ◽  
Vol 40 (4) ◽  

Abstract UNS G62100 is a tough, shock resisting, case-hardening chromium-vanadium steel. It has high fatigue resistance in the heat treated condition. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-458. Producer or source: Alloy steel mills and foundries.


Alloy Digest ◽  
2020 ◽  
Vol 69 (1) ◽  

Abstract Lucefin Group C45U is a medium-carbon, non-alloy cold-work tool steel. It is primarily used in the non-heat-treated condition. For special applications it is used in the quenched and tempered condition. Owing to its low hardenability, C45U develops a fully hardened zone that is relatively thin, even when quenched drastically. Thicker sections have a hard case over a tough core. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming and joining. Filing Code: TS-784. Producer or source: Lucefin S.p.A.


2012 ◽  
Vol 30 (2) ◽  
pp. 188 ◽  
Author(s):  
Dong-Mei LI ◽  
Cheng-Hou WU ◽  
Xiu-Lin YE ◽  
Cheng-Ye LIANG

2013 ◽  
Vol 21 (1) ◽  
pp. 43-51
Author(s):  
O. Bapokutty ◽  
◽  
Z. Sajuri ◽  
J. Syarif ◽  
◽  
...  

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1009-1020 ◽  
Author(s):  
William F Sheridan ◽  
Nadezhda A Avalkina ◽  
Ivan I Shamrov ◽  
Tatyana B Batyea ◽  
Inna N Golubovskaya

Abstract The switch from the vegetative to the reproductive pathway of development in flowering plants requires the commitment of the subepidermal cells of the ovules and anthers to enter the meiotic pathway. These cells, the hypodermal cells, either directly or indirectly form the archesporial cells that, in turn, differentiate into the megasporocytes and microsporocytes. We have isolated a recessive pleiotropic mutation that we have termed multiple archesporial cells1 (macl) and located it to the short arm of chromosome 10. Its cytological phenotype suggests that this locus plays an important role in the switch of the hypodermal cells from the vegetative to the meiotic (sporogenous) pathway in maize ovules. During normal ovule development in maize, only a single hypodermal cell develops into an archesporial cell and this differentiates into the single megasporocyte. In macl mutant ovules several hypodermal cells develop into archesporial cells, and the resulting megasporocytes undergo a normal meiosis. More than one megaspore survives in the tetrad and more than one embryo sac is formed in each ovule. Ears on mutant plants show partial sterility resulting from abnormalities in megaspore differentiation and embryo sac formation. The sporophytic expression of this gene is therefore also important for normal female gametophyte development.


2002 ◽  
Vol 82 (4) ◽  
pp. 751-752 ◽  
Author(s):  
L. Andersen ◽  
T. Warkentin ◽  
O. Philipp ◽  
A. Xue ◽  
A. Sloan

DS Admiral, a yellow cotyledon field pea (Pisum sativum L.) cultivar, was released in 2000 by Agriprogress Inc., Morden, Manitoba. DS Admiral has a semileafless leaf type, powdery mildew resistance, medium sized, round seeds, and good yielding ability. DS Admiral is adapted to the field-pea-growing region of western Canada. Key words: Field pea, Pisum sativum L., cultivar description, powdery mildew resistance


Sign in / Sign up

Export Citation Format

Share Document