Total Weight Of Seeds Research Articles

Acacia tortilis (Forsk) Hayne subsp raddiana (Savi) in a North African pseudo-savanna: Morphological variability and seed characteristics

Acacia tortilis (Forsk) Hayne subsp. raddiana (Savi) Brenan (Family Fabaceae; subfamily Mimosoideae) is a pioneer tree of dry areas and it is a drought-resistant species. In spite of its several uses, there are no published studies which deal with relation between its adaptive features and fruit production for the Tunisian Arboretum. For this reason, a study was carried out in Bouhedma National Park to investigate morphology and seed production of A. tortilis pseudo-savanna for three successive years: 2006, 2007 and 2008. Two hundred and fifty trees from five plots in the three integral protection zones from five altitudes were studied to assess their genetic variation based on morphological parameters and fruit characteristics. The averages of the main descriptive morphological values of A. tortilis trees are 3.52 m of the height, 13.83 cm of the diameter at the base, 7.47 cm for the diameter at 1.30 m, 4.46 m for the diameter of crown North-South and 4.15 m for the diameter of crown East-West. The means of the main descriptive morphological values of pods are for the number of seeds before maturity 189.36, for number of seeds after maturity 50.625, for loss in pods 85.06%, for total number of seeds 406.11, for total weight of seeds 14.12 g and for the percentage of seeds infested 32.72%. Most of the measured parameters showed significant differences that indicate a high genetic diversity. Bruchidus has been recorded as a serious pest of A. tortilis seeds. The infested of seeds is directly related to number and loss in pods, number and weight of seeds (Pr <0.0001). Key words: Acacia tortilis, altitude, morphological diversity, pods, production, seeds.

Identification of a major QTL for silique length and seed weight in oilseed rape (Brassica napus L.)

Silique length (SL) and seed weight (SW) are two important yield-related traits controlled by quantitative trait loci (QTL) in oilseed rape (Brassica napus L.). The genetic bases underlying these two traits are largely unknown at present. In this study, we conducted QTL analyses for SL and SW using 186 recombinant inbred lines (RILs) derived from a cross between S1, an EMS mutant with extremely long siliques and large seeds, and S2, an inbred line with regular silique length and seed size. RILs were grown in Wuhan in the 2008/09 (SS09) and 2009/10 (SS10) growing seasons, and mean SL and SW for each line were investigated. Ten non-redundant QTL were identified for SL. Of these, a major QTL, cqSLA9, consistently explained as much as 53.4% of SL variation across environments. The others are minor QTL and individually explained less than 10% of the SL variation. Nine non-redundant QTL were identified for SW. Of which, one major QTL, cqSWA9, explained as much as 28.2% of the total SW variation in the SS09 and SS10 environments. In addition, three additive by additive interactions with small effects were detected for SL, and no interactions were detected for SW. Interestingly, the two major QTL, cqSLA9 for SL and cqSWA9 for SW colocalized in the same chromosomal region and were integrated into a unique QTL, uqA9. The S1 allele at this locus increases both SL and SW, suggesting that uqA9 has pleiotropic effects on both SL and SW. The existence and effect of uqA9 was confirmed in genetically different RILs derived from the cross between S1 and No2127, a resynthesized DH line having regular silique length and seed size. Individuals in one residual heterozygous line for cqSLA9 showed significant difference in silique length. The results in this study revealed that silique length in the S1 mutant is mainly controlled by the cqSLA9 locus, which will be suitable for fine mapping and marker-assisted selection in rapeseed breeding for high yield.

The effect of experimental warming on leaf functional traits, leaf structure and leaf biochemistry in Arabidopsis thaliana.

BackgroundThe leaf is an important plant organ, and how it will respond to future global warming is a question that remains unanswered. The effects of experimental warming on leaf photosynthesis and respiration acclimation has been well studied so far, but relatively little information exists on the structural and biochemical responses to warming. However, such information is very important to better understand the plant responses to global warming. Therefore, we grew Arabidopsis thaliana at the three day/night temperatures of 23/18°C (ambient temperature), 25.5/20.5°C (elevated by 2.5°C) and 28/23°C (elevated by 5°C) to simulate the middle and the upper projected warming expected within the 21st century for this purpose.ResultsThe 28/23°C treatment significantly reduced the life span, total biomass and total weight of seeds compared with the other two temperatures. Among the three temperature regimes, the concentrations of starch, chlorophyll, and proline were the lowest at 28/23°C, whereas the total weight of seeds, concentrations of chlorophyll and proline, stomatal density (SD), stomatal conductance (gs), net CO2 assimilation rate (A) and transpiration rate (E) were the highest at 25.5/20.5°C. Furthermore, the number of chloroplasts per cell and mitochondrial size were highest at 25.5/20.5°C and lowest at 28/23°C.ConclusionsThe conditions whereby the temperature was increased by 2.5°C were advantageous for Arabidopsis. However, a rise of 5°C produced negative effects, suggesting that lower levels of warming may benefit plants, especially those which belong to the same functional group as Arabidopsis, whereas higher levels of warming may produce negative affects. In addition, the increase in A under moderately warm conditions may be attributed to the increase in SD, chlorophyll content, and number of chloroplasts. Furthermore, starch accumulation in chloroplasts may be the main factor influencing chloroplast ultrastructure, and elevated temperature regulates plant respiration by probably affecting mitochondrial size. Finally, high SOD and CAT activities may enable plants grown at elevated temperatures to exhibit relatively high tolerance to temperature stress, thus alleviating the harmful effects of superoxide anion radicals and hydrogen peroxide.

Early seeding growth of fluted pumpkin as affected by seed and pod sizes under nursery and feld conditions

Inter-relationships among some pod, seed and seedling characters in fluted pumpkin (Telfairia occidentalis Hook. F.) were studied in the search for criteria for judicious selection of seed(s) for cultivation. Seeds obtained from four pods of various sizes were sorted into five weight classes namely: W1 (= 11g), W2 (12-16g), W3 (17-21g), W4 (22-26g) and (W5 = 27g). Seedlings were first raised in a nursery and subsequently transplanted into the field. Whole pod weight was positively and significantly correlated with both total weight of seeds and empty pod weight (r2= 0.981 and 0.972 respectively) but seed quality could not be ascertained from total seed weight. Number of seeds per pod showed no significant correlations with pod characteristics such as weight, length, circumference and diameter. Seeds in weight class W1 showed no emergence. Percentage emergence in the other weight classes ranged from 70% (W5) to 97% (W4). There was no significant effect of seed weight on rate of emergence, length and girth of vine and number of leaves per seedling in the nursery. Higher values of length of vine and numbers of nodes and leaves were obtained from W4 and W5 compared with W2 and W3 on the field after transplanting.Keywords: fluted pumpkin, telfairia occidentalis, pod characteristics, seed quality Nigerian Journal of Horticultural Science Vol. 9 2005: 35-42

(382) Application of a Molecular Marker for Berry Seed Size to Two Populations of Grapevines (Vitis sp.) Developed in a Breeding Program

The development of grapevines with berries with small seed traces, so-called seedless grapes, is a costly process. Marker assisted selection would save time and money. Adam-Blondin et al. (Vitis 40:147. 2001) demonstrated that a sequence characterized amplified region, SCC8, could identify seedless grapevine cultivars in European accessions of Vitisvinifera L. We have applied this marker to two populations of grapevines in a breeding program in California. One population consisted of 100 individuals while the second had 109. The two crosses had a common female parent, derived from `Flame Seedless'. Fruit were evaluated over several seasons for parameters including total weight of seeds or traces. DNA was isolated from leaves during the spring. Amplification was carried out with SCC8 primers, followed by digestion with Bgl II, and agarose gel electrophoresis. Individuals were scored as homozygous SCC8+ (small seeded), heterozygous SCC8+/scc8-(intermediate sized seeds), or homozygous scc8-(large seeded) and mean total seed weight per berry was calculated for each genetic class. In the first population, the number of individuals in the inferred genotypes fit an expected 1:2:1 distribution (χ2 = 0.480, P&gt; 0.787) and seed weights for each genetic class were reasonable. For the second population, it was necessary to postulate a null allele in one parent, with a 1:1:1:1 expected distribution for genotypes SCC8+/SCC8+, SCC8+/null, SCC8+/scc8-, and scc8-/null. The actual distribution was in agreement with this model (χ2 = 4.379, P&gt; 0.223). The genotype SCC8+/null had the SCC8+ marker and total seed weight &gt;10 mg per berry. Large seeded individuals and heterozygotes could be reliably identified with this marker.

QUANTITATIVE CHARACTERS OF SEEDS AND CONES IN LARIX CHINENSIS

Larix chinensis is an endangered plant distributed only in the Qinling Mountains of Shaanxi Province, China. It forms pure forest stands that have important ecological functions of water and soil conservation at timberline at altitudes of 2 600 - 3 600 m. Studies on the quantitative characteristics of seeds and cones are necessary for understanding why this species is endangered. The variation among 7 quantitative characteristics of seeds and cones of Larix chinensis in different environments were examined, and the relationships between seed and cone characteristics and environmental factors were analyzed using one-way ANOVA and Pearson correlation coefficients. The results showed that characteristics of the seeds and cones in different environments were significantly different. Compared to the other populations, variance analysis indicated that there were greater numbers of seeds per cone (107.22±47.3), greater total weight of seeds per plant (25.47± 6.55 ), greater total weight of cones per plant (217.80±157.26), greater annual weight of cones (2 021± 0.44 ), a greater number of cones per plant (4 580±2 440.7), and a greater number of seeds per cone ( 72.8 ±5.83) in Guangtou Shan. Multiple comparison analysis demonstrated that the weight of seeds per plant, the average weight of a cone and the total weight of cones per tree were greater in small populations. The coefficient of variation of seed and cone characteristics in a population was high. The CV of the number of cones per plant was 63.47% and the weight of 1 000 seeds was 19.17%, indicating that the 7 measured characteristics of seeds and cones varied greatly within and among populations. The seed and cone characteristics showed a negative correlation with altitude, slope and slope direction and a positive correlation with age. The seed number per cone was positively correlated to annual average temperature (p0.05) and negatively correlated to mean temperature in January (p0.05). The size of seed was positively correlated with the total number of seeds. There was no trade-off between the size of seed and the total number of seeds.

Effect of increasing doses of nitrogen and sulphur on chemical composition of plants, yields and seed quality in winter rape

&amp;nbsp;In 1999, the effect of increasing levels of nitrogen at the initial (13.9 mg.kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) and increased (40 mg.kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) level of watersoluble sulphur (S&lt;sub&gt;wat&lt;/sub&gt;) was studied in winter rape (cv. Lirajet) grown in pots. A synergetic effect of nitrogen on concentrations of Ca and Mg was demonstrated in the growth stages DC 20&amp;ndash;29 and 31&amp;ndash;39. Levels of P and K were balanced. In variants with a low content of S&lt;sub&gt;wat &lt;/sub&gt;in soil to 40 mg.kg&lt;sup&gt;&amp;ndash;1 &lt;/sup&gt;of soil S concentration increased. With the increasing dose of N the content of S decreased from 1.00% to 0.78% and from 0.68% to 0.38% in DC 20&amp;ndash;29 and DC 31&amp;ndash;39, respectively. An increased level of S in soil changed the ratio N/S. In variants with a natural (i.e. low) content of S in soil, this ratio widened with the increasing dose of N from 8.06 to 25.15 while in variants with an increased level of S in soil it ranged from 3.24 to 5.85 in the growth stage DC 20&amp;ndash;29. Increasing doses of N widened the ratio N/P regardless to concentration of S in plants. In individual growth stages the ratio P/S was markedly narrowed by changing contents of S in soil. The highest yields were obtained in the variant with an optimum concentration of all elements in plants and S contents above 0.6% and/or about 0.4% in growth stages DC 20&amp;ndash;29 and DC 31&amp;ndash;39, respectively. The obtained yields demonstrated a highly significant effect of N and S on seed yields. At a low concentration of sulphur in plants the yield of seed increased only to the dose N&lt;sub&gt;3&lt;/sub&gt;(i.e. 0.9 g N per pot); thereafter, it gradually decreased. An increased level of S in soil showed a positive effect on seed yields. Higher doses of N widened the ratio straw/seeds from 2.46 to 7.69; at higher levels of S in soil, an opposite trend was observed. In variants with a low content of S the number of branches and pods increased proportionally with increasing doses of N. On the other hand, increased levels of S reduced the number of branches and pods. At a low level of S in soil the total weight of seeds per pod decreased with the increased supply of N from 69.9 mg to 20.4 mg. At increased levels of S the weight of seeds per pod increased from 61.9 mg to 79.8 mg. Results of field experiments in four different localities corroborated a positive effect of S (in interaction with N) on its concentration in plants. The seed yield was significantly increased. In 2000, results from all localities were markedly influenced by climatic conditions; however average results of all experiments showed that S increased seed yields depending on the dose of N by 2.5 and 5.9%. An optimum nutrition of plants with all elements (including S) results in improved utilisation and increased yields.

Relationships between seed set and fruit weight and shape of nashi (Pyrus serotinaRehder varcultaRehder)

Abstract The relationships between seed set and fruit weight and shape were studied on four nashi (Pyrus serotina Rehder var culta Rehder) cultivars Hosui, Kosui, Nijisseiki, and Shinsui. The carpel number ranged between four and eight per fruit with each carpel having the capacity to carry two seeds. The number of seeds per fruit was significantly correlated with fruit weight with ‘Nijisseiki’ showing the highest fruit-weight increase per seed. The seed number per carpel and the total weight of seeds per carpel were related to fruit shape. Even seed distribution around the fruit core was related to evenly shaped fruit. On the basis of the levels of seed set observed, considerable potential exists for raising the nashi quality by optimising pollination and seed set.

Male and Female Reproductive Success in the Hermaphroditic Plant Phlox drummondii

Three sets of reciprocal crosses were performed among 12 plants of the hermaphroditic annual Phlox drummondii, a self-incompatible species. Each plant was used as both a pollen donor and a pollen recipient for estimating both male and female reproductive success. For each cross, pollen germinability, the number of seeds produced, the weight of each seed produced, and the total weight of all seeds were measured. The performances of the 12 plants as females varied significantly for all traits measured for each set of crosses. Among the 12 plants as males, significant variation occurred only for the total seed weight in cross 1 and for the number of seeds and the total seed weight in cross 3. Within cross 3, females discriminated among males, with some males producing more or fewer fruits than expected. Cross set 3 produced fewer and smaller seeds than cross sets 1 and 2, indicating that resource limitation was a factor. Discrimination among males and resource limitation within cross set 3 may be linked. Correlations for individual traits between the performances of the 12 plants as males and females were generally not significant. Variance among the performances of the plants as females was significantly greater than the variance among males.

EFFECTS OF APEX REMOVAL AND NUTRIENT SUPPLEMENTATION ON BRANCHING AND SEED PRODUCTION IN THLASPI ARVENSE (BRASSICACEAE).

The shoot apex of a plant may be damaged by herbivory, weather conditions, or other factors, leading to growth of some axillary buds into branches. This alteration of branching pattern can affect the location and extent of seed production. I examined the effects of removal of the shoot apex and of mineral nutrient addition on branching and seed production in Thlaspi arvense. Individual plants received no, early, or late apex removal and no, early, or late nutrient addition in a two-way factorial experiment. Apex removal led to greater production of secondary branches. Total seed weight per plant was higher for early- than late-removal plants under all nutrient treatments, but intact controls produced the highest total weight of seeds in two of three nutrient treatments, because their seeds were heavier. Addition of nutrients increased the numbers of secondary branches, fruits, and seeds, and the average and total weight of seeds produced. Apex removal resulted in increased seed production only when it occurred early and when nutrients were added at the same time. Resource availability and plant phenology can be influential in determining the effects of apical damage on seed production, and their effects in combination may differ from their individual effects.

Sexual Selection in Raphanus sativus: Experimental Data on Nonrandom Fertilization, Maternal Choice, and Consequences of Multiple Paternity

We determined the paternity of seeds in the multiseeded fruits of Raphanus sativus in order to measure the potential mechanisms of sexual selection after experimental pollination with mixed pollen loads. We also compared singly and multiply sired fruits. We found effects of pollen-donor identity on the number of ovules fertilized, the position of ovules fertilized, the fruit set, seeds per fruit, and seed weight. One pollen donor was inferior by all measures and had the slowest pollen germination. The effect of pollen-donor identity may be attributed to male-male competition because it is uniform over the maternal plants, or the effect may be caused by all females "choosing" in the same way. Another effect, that multiply sired fruits have a greater total weight of seeds per fruit than do fruits sired singly by any of the pollen donors, appears to be a case of maternal choice. Comparison of the seed sizes of two of the pollen donors suggests that competition between seeds for resources may be more intense in multiply sired fruits; however, seeds sired by another pollen donor were larger in multiply sired fruits than in singly sired fruits. Microgametophytic competition was not evident when the amount of pollen from a single donor was varied. Thus, in R. sativus, the consequences of microgametophytic competition among several pollen donors may be far more profound than competition among the male gametophytes produced by one pollen donor.

Response of cow pea (Vigna unguiculata L.) to CO2 enrichment environment on growth, dry-matter production and yield components at different stages of vegetative and reproductive growth

SUMMARYThis study examines the effects of increased atmospheric carbon dioxide concentrations on vegetative and reproductive growth and partitioning of biomass during pod and seed development of cow pea in controlled environment chambers at 350, 675, and 1000μl CO2/l.The length of main stem and branches, the number of leaves and branches, and leaf area were all greater at high CO2 than at low CO2 concentration. The appearance of flowers was 10–12 days earlier in high CO2 than in ambient CO2 atmosphere. The senescence of leaves started about 7 days earlier in plants grown at 675 and 1000 μl CO2/l than in those grown at 350 μl CO2/l. The rate of leaf senescence was more rapid in 1000 μl/l than in 675 μl CO2/l. The dry weight of roots, stems and leaves increased with CO2 enrichment, being greater in 675 μl/l than in 1000 μl CO2/l. Plants grown in 675 and 1000 μ1/1 produced more pods and seeds than in 350 μl CO2/l. Total seed weight and number of pods, as well as number of seeds per pod, were significantly greater in CO2 enriched atmosphere than ambient CO2 level. Although CO2 enrichment caused a significant increase in the total number and weight of seeds as well as pods, it did not affect the ratio of seed dry weight to the total dry weight of above-ground plant parts (harvest index). It is concluded from the present investigation that CO2 enrichment significantly enhanced vegetative as well as reproductive growth resulting in the increase in yield and early plant maturation in this leguminous crop.

Effects of 2,4-D on Seed Production and Embryo Development of Curly Dock

Lithium salt of (2,4-dichlorophenoxy)acetic acid (2,4-D) (1000 ppm) was sprayed on plants of curly dock (Rumex crispus L.) 12 days before anthesis, at an thesis, 7 days after anthesis, and 34 days after anthesis. Treatment 12 days before anthesis completely prevented the formation of viable seeds. Two percent of the seeds had minute embryos after treatment at anthesis, but even these seeds did not germinate. Embryos were present in 91% of the seeds from plants treated 7 days after anthesis. These embryos ranged in size from 0.5 to 2.5 mm. The total weight of seeds obtained was significantly less than the control and only 5 to 15% of these seeds were capable of germination. Spraying the inflorescences 34 days after anthesis did not affect the number of seeds produced or seed viability. Almost all plants remained alive after the harvest.