Effect of ovule position on seed maturation and seed weight in Ulex europaeus and Ulex gallii (Fabaceae)

1996 ◽  
Vol 74 (6) ◽  
pp. 848-853 ◽  
Author(s):  
David Gutiérrez ◽  
Rosa Menéndez ◽  
José R. Obeso

We examined the effect of ovule position within the pod on the probability of seed maturation and on seed weight in two woody legumes, Ulex europaeus and Ulex gallii. Results showed that ovule position had a significant effect on the probability of seed maturation in both species. Ovules in a central position were found to have a higher probability of maturation in U. europaeus, whereas those in a stylar position were favored in U. gallii. Ulex europaeus showed no effect of position on seed weight. The smallest seed within the pod was more frequently at stylar positions in U. gallii. These results might be explained by several non-exclusive hypotheses: time of fertilization, constraints on seed development (e.g., fruit shape and access to maternal resources), and genetic quality. The effects of seed weight on progeny performance estimated as probability of germination and seedling weight were tested in a laboratory experiment. Neither U. europaeus nor U. gallii exhibited any effect of seed weight on the probability of germination. However, seedling weight was dependent on seed weight in both species. Keywords: woody legumes, probability of maturation, seed position, seed weight.

2019 ◽  
Vol 180 (1) ◽  
pp. 59-65
Author(s):  
M. V. Gurkina

Background. The problem of a deficit in vegetable protein and the need to diversify agricultural produce require involvement of new and little-known crops, such as cowpea, in the production. Cowpea (Vigna unguiculata (L.) Walp.) is a high-protein leguminous crop; its breeding and production have been intensified in Russia only in recent years. The study of the VIR collection, carried out at the Institute’s branch in Astrakhan, makes it possible to disclose the crop’s breeding potential. Objective: Studying the range of variability and tracing the relationships of economically valuable traits in vegetable (green pod) cowpea under the conditions of Astrakhan Province.Materials and methods. In 2008‑2010, a study was implemented at an experiment plot of the Astrakhan branch of VIR. Thirty- three accessions of green pod cowpea from the VIR collection were studied to analyze the variability of 12 phenotypic traits. Positive and negative correlations were identified between the following characters: interphase periods (flowering, industrial ripeness and seed maturation), shape of the shrub, lengths of the stem and to the first pod, length and weight of the pod, number of seeds per pod, presence of a parchment layer and fiber in pod valves, pod yield per plant, number of pods and peduncles, seed weight per plant, and weight of 1000 seeds.Results and conclusion. Medium variability was observed for such characters as the interphase periods ‘shoots–industrial ripeness’ and ‘shoots– seed maturation’, number of seeds per pod, and weight of 1000 seeds: the coefficient of variation (CV) was 15‑18%. High variation was registered for the length and weight of the pod (CV = 26‑32%), shrub shape, stem length, and length of the stem up to the first pod (CV = 35‑37%). The widest ranges of variability were demonstrated in the quantitative yield characters of cowpea accessions: number of pods per plant (CV = 33‑49%), number of flower stalks (CV = 38‑51%), and seed weight per plant (CV = 38‑44%), which means that cowpea yield is quite susceptible to weather conditions. During the three years of studying, the lowest levels of variability in economically valuable traits were characteristic of the accessions of the early-ripening group: k‑668 and k‑873 (China); mid- ripening group: k‑971 (India); and late-ripening group: k‑141 (China). Cowpea pod productivity depended to the greatest degree from mean values of the number of pods per plant (r = 0,73) and the number of peduncles (r = 0,71). The identified correlations in the productivity components make it possible to optimize the selection of accessions promising as source materials for the development of new high-yielding cultivars.


2008 ◽  
Vol 276 (1657) ◽  
pp. 707-715 ◽  
Author(s):  
Elisabeth Bolund ◽  
Holger Schielzeth ◽  
Wolfgang Forstmeier

The classical version of the differential allocation hypothesis states that, when females reproduce over their lifetime with partners that differ in their genetic quality, they should invest more in reproduction with high-quality males. However, in species with lifetime monogamy, such as the zebra finch, partner quality will typically remain the same. In this case, the compensatory investment (CI) hypothesis predicts higher investment for low-quality males, because low genetic quality offspring are more dependent on maternal resources. Here, we show that female zebra finches invested more resources, both in terms of egg volume and yolk carotenoid content, when paired to a low genetic quality male, as judged from his previous ability to obtain extra-pair paternity in aviary colonies. We also found that females deposited slightly larger amounts of testosterone into eggs when paired to a low parental quality male, as judging from his previous success in rearing offspring. This is, to our knowledge, the first experimental support for the CI hypothesis in a species with lifetime monogamy. We stress that in more promiscuous species, the benefits of classical differential allocation may partly be neutralized by the supposed benefits of CI.


Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 568-569 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside

A 2-year experiment was conducted to determine the time interval between flowering and viable seed production in common milkweed (Asclepias syriacaL.). A high percentage of seeds harvested 6 weeks after flowering germinated. Seeds harvested 6 and 7 weeks after flowering resulted in seedlings with significantly shorter radicles and hypocotyls than seeds harvested 8 weeks after flowering. There was a close association between seed weight and radicle and hypocotyl length. Common milkweed produced viable seeds 5 to 6 weeks after flowering.


Botany ◽  
2008 ◽  
Vol 86 (5) ◽  
pp. 466-474 ◽  
Author(s):  
David J. Susko ◽  
Michelle Clubb

We examined ovule positional effects on patterns of ovule development within linear fruits of the invasive weed, dame’s rocket, Hesperis matronalis L. Fruits were collected from two sites in southwestern Ontario, Canada. The majority of ovules within fruits were aborted early in development. Emergent patterns of ovule abortion and seed maturation within fruits were nonrandom and dependent on ovule position. The probability of seed maturation within individual fruits decreased significantly from basal to distal ends, suggesting an intrafruit resource gradient. Self-pollinated flowers at one site produced fruits with a similar pattern of seed maturation as was found for open-pollinated plants. However, cross-pollinated flowers produced fruits in which the pattern of seed maturation was reversed; more seeds were matured at the distal ends rather than the basal ends of fruits, indicative of a fertilization gradient. Analysis of pollen-tube growth showed that ovule failure may not be attributed to pollen limitation. For seeds produced via hand-pollinations, we found no relationship between seed mass and seedling biomass, although seeds from self-pollinations germinated more readily than did seeds from cross-pollinations. While patterns of ovule fate in H. matronalis can be manipulated by pollen source, the effects of such patterns on plant fitness are yet to be determined.


2006 ◽  
Vol 84 (8) ◽  
pp. 1259-1265 ◽  
Author(s):  
David J. Susko

I examined the effect of ovule position on patterns of ovule development within the linear pods of black locust, Robinia pseudoacacia L. Fruits were sampled from three sites in southwestern Ontario, Canada. Approximately two-thirds of all ovules failed to show visible signs of fertilization or development. Patterns of seed maturation and abortion within fruits were nonrandom and depended on ovule position. The probability of seed maturation within individual fruits decreased significantly from the distal to basal ends, suggesting the existence of a fertilization gradient. Seeds at the basal ends of fruits were also lighter than more distally located seeds. While seed mass did not influence the likelihood of germination, seed mass was positively correlated with seedling size. Hence, ovule position exerts an influence on offspring vigour and has the potential, ultimately, to affect plant fitness.


Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Nasser Aliasgharzad ◽  
Mohammad Neyshabouri ◽  
Ghobad Salimi

AbstractMycorrhizal symbiosis can potentially improve water uptake by plants. In a controlled pot culture experiment, soybean plants were inoculated with two species of arbuscular mycorrhizal fungi, Glomus mosseae (Gm) or Glomus etunicatum (Ge), or left non-inoculated (NM) as control in a sterile soil. Four levels of soil moisture (Field capacity, 0.85 FC, 0.7 FC, 0.6 FC) in the presence or absence of the Bradyrhizobium japonicum, were applied to the pots. Relative water content (RWC) of leaf at both plant growth stages (flowering and seed maturation) decreased with the dryness of soil; RWC was higher in all mycorrhizal than non-mycorrhizal plants irrespective of soil moisture level. At the lowest moisture level (0.6 FC) Ge was more efficient than Gm in maintaining high leaf RWC. Leaf water potential (LWP) had the same trend as RWC in flowering stage but it was not significantly influenced by decrease in soil moisture to 0.7 FC during seed maturation stage. Seed and shoot dry weights were affected negatively by drought stress. Mycorrhizal plants, however had significantly higher seed and shoot dry weights than non-mycorrhizal plants at all moisture levels except for seed weight at 0.6 FC. Root mycorrhizal colonization was positively correlated with RWC, LWP, shoot N and K, and seed weight, implying improvement of plant water and nutritional status as a result of colonization. Regardless of moisture treatments, bacterial inoculation caused a significant enhancement in N content and the highest N occurred in rhizobial inoculated plants at 0.85 FC and 0.7 FC. Shoot K was enhanced considerably by both bacterial and fungal inoculations, particularly in plants with dual inoculations where the highest shoot K levels were found. The relatively higher shoot and seed dry weights in plants inoculated with both G. etunicatum and B. japonicum could be ascribed to their higher RWC and LWP, suggesting that drought avoidance is main mechanism of this plant-microbe association in alleviation of water stress in soybean.


1990 ◽  
Vol 66 (4) ◽  
pp. 388-392 ◽  
Author(s):  
G. E. Caron ◽  
B. S. P. Wang ◽  
H. O. Schooley

Cones were collected in 1984 at the time of natural seed dissemination from 18 open-pollinated, 30-year-o!d white spruce (Picea glauca(Moench) Voss) trees at 1.2, 2.4, and 4.9 m spacings in a demonstration seed production area at Petawawa National Forestry Institute. Cones were stored in a well-ventilated building for 2 to 6 weeks before seed extraction.Cones length, full-seed-yield per cone, and full-seed weight were greatest for cones collected from trees at the 1.2 m spacing. When cones were stored for 2 weeks, non-prechilled and prechilled seeds averaged 32.0 ± 1.0% [Formula: see text] and 62.3 ± 1.0% germination, respectively. When cones were stored for 6 weeks, non-prechilled and prechilled seeds averaged 61.3 ± 1.2% and 94.7 ± 0.5% germination, respectively. The higher germination percentage, germination rate, and lower tree to tree variation for prechilled seeds from cones stored for 6 weeks indicate that seed maturation was promoted by post-harvest cone storage prior to seed extraction. Average seed dormancy remained about the same from 2 to 6 weeks of storage; however, seeds from some trees became more dormant with the storage whereas those from others became less dormant. Relationship between seed weight and germination was weak. Key words: Cone storage, seed prechilling, germination percentage, germination rate, seed maturation, seed dormancy, seed weight, seed sorting.


Web Ecology ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 22-26 ◽  
Author(s):  
J. A. Crisóstomo ◽  
H. Freitas ◽  
S. Rodríguez-Echeverría

Abstract. Acacia longifolia, an Australian leguminous tree, is one of the main invasive plant species in the coast of Portugal and a major threat to the native vegetation in the Reserva Natural das Dunas de São Jacinto. With the establishment of this exotic species, other native woody leguminous species such as Cytisus grandiflorus and Ulex europaeus have been displaced from their original areas. Several factors are involved in the process of biological invasion by exotic species. Plant physiology and development, characteristic of each species, can give certain advantages in the establishment and colonization of new areas. We tested if there are differences in the Relative Growth Rate (RGR) of the exotic and native species because this could be relevant in the first stages of the invasion process. Our results showed that A. longifolia was the species with lowest RGR. Therefore, other factors apart from RGR might explain the invasion of coastal dunes by this species. We propose that A. longifolia might be a better competitor than the two native legumes and that this process might be mediated by the interaction with soil organisms.


1998 ◽  
Vol 80 (08) ◽  
pp. 310-315 ◽  
Author(s):  
Marie-Christine Bouton ◽  
Christophe Thurieau ◽  
Marie-Claude Guillin ◽  
Martine Jandrot-Perrus

SummaryThe interaction between GPIb and thrombin promotes platelet activation elicited via the hydrolysis of the thrombin receptor and involves structures located on the segment 238-290 within the N-terminal domain of GPIbα and the positively charged exosite 1 on thrombin. We have investigated the ability of peptides derived from the 269-287 sequence of GPIbα to interact with thrombin. Three peptides were synthesized, including Ibα 269-287 and two scrambled peptides R1 and R2 which are comparable to Ibα 269-287 with regards to their content and distribution of anionic residues. However, R2 differs from both Ibα 269-287 and R1 by the shifting of one proline from a central position to the N-terminus. By chemical cross-linking, we observed the formation of a complex between 125I-Ibα 269-287 and α-thrombin that was inhibited by hirudin, the C-terminal peptide of hirudin, sodium pyrophosphate but not by heparin. The complex did not form when γ-thrombin was substituted for α-thrombin. Ibα 269-287 produced only slight changes in thrombin amidolytic activity and inhibited thrombin binding to fibrin. R1 and R2 also formed complexes with α-thrombin, modified slightly its catalytic activity and inhibited its binding to fibrin. Peptides Ibα 269-287 and R1 inhibited platelet aggregation and secretion induced by low thrombin concentrations whereas R2 was without effect. Our results indicate that Ibα 269-287 interacts with thrombin exosite 1 via mainly electrostatic interactions, which explains why the scrambled peptides also interact with exosite 1. Nevertheless, the lack of effect of R2 on thrombin-induced platelet activation suggests that proline 280 is important for thrombin interaction with GPIb.


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