Seed production in woodland and isolated trees of Eucalyptus melliodora (yellow box, Myrtaceae) in the South Western Slopes of New South Wales

2000 ◽  
Vol 48 (6) ◽  
pp. 681 ◽  
Author(s):  
G. E. Burrows
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Physical Parameters ◽  
Mixed Mating ◽  
Isolated Trees ◽  
South Wales ◽  
Large Numbers ◽  
The Mean ◽  
Viable Seeds ◽  
Number Of Seeds

Seed production in woodland and isolated Eucalyptus melliodora Cunn. ex Schauer trees was investigated. Measurement of physical parameters such as mean capsule weight, mean seed weight and mean ratio of the weight of the capsule contents to the weight of the empty capsule showed no significant differences between woodland and isolated trees. In contrast, reproductive output as measured by mean number of seeds per capsule, mean number of seeds per 10 g of capsule contents and mean seed weight as a percentage of the weight of the capsule contents, was significantly lower (45–48% less) in isolated trees than in woodland trees. Mean percentage seed germination was also significantly lower (14% less) in the isolated trees and the mean number of viable seeds per 10 g of capsule contents was only 38% of the woodland trees. These results indicate that E. melliodora, like many eucalypts, has a mixed mating breeding system with preferential outcrossing but is also capable of self pollination leading to a reduction in seed yield and viability. The woodland and isolated trees produced a mean of 4.6 and 2.1 seeds per capsule, respectively. It would be relatively easy to collect large numbers of seeds from isolated trees of E. melliodora and subsequently propagate potentially genetically inferior plants.

Characterisation of naturalised strains of Trifolium subterraneum var. brachycalycinum cv. Clare in northern New South Wales

1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Weight ◽  
New South ◽  
New South Wales ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Median Number ◽  
South Wales ◽  
The Mean ◽  
Floral Characters ◽  
Number Of Seeds

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.

scholarly journals Morphological characterization and genetic diversity in lentil (Lens culinaris medikus ssp. Culinaris) germplasm

2014 ◽  
Vol 4 (1) ◽  
pp. 70-76
Author(s):  
KU Ahamed ◽  
B Akhter ◽  
MR Islam ◽  
MR Humaun ◽  
MJ Alam
Keyword(s):  
Seed Weight ◽  
Female Flower ◽  
Morphological Characterization ◽  
Flower Initiation ◽  
Mean Values ◽  
Maximum Value ◽  
Cluster Distance ◽  
The Mean ◽  
100 Seed Weight ◽  
Number Of Seeds

Genetic divergence of 110 lentil germplasm with checks was assessed based on morphological traits using multivariate analysis. Mahalanobis generalized distance (D2) analysis was used to group the lentil genotypes. Significant variations among lentil genotypes were observed in respect of days to 1st flowering, days to 50% flowering, days to maturity, plant height, and number of pods per peduncle, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant. Considering the mean values, the germplasm were grouped into ten clusters. The highest number of genotypes (17) was in cluster X and lowest (5) both in cluster II and IV. Cluster IV had the highest cluster mean for number of pods per plant (297.08), number of seeds per plant (594.16), 100 seed weight (1.44 g) and yield per plant (8.53 g). Among them, the highest inter-cluster distance was obtained between the cluster IV and I (24.61) followed by IV and III (22.33), while the lowest was between IX and II (1.63). The maximum value of inter-cluster distance indicated that genotypes belonging to cluster IV were far diverged from those of cluster I. The first female flower initiation was earlier in BD-3812 (49 days) in cluster I and cluster IV had highest grain yield per plant (8.53). BD-3807 produced significant maximum number of pods per plant (298.40) in cluster IV. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21095 Int. J. Agril. Res. Innov. & Tech. 4 (1): 70-76, June, 2014

Seed production in Cardiocrium cordatum: effects of nitrogen and dry mass availability of a plant

2006 ◽  
Vol 84 (5) ◽  
pp. 805-812
Author(s):  
Satoki Sakai ◽  
Akiko Sakai ◽  
Kohta Fujioka
Keyword(s):  
Mass Loss ◽  
Seed Production ◽  
Plant Size ◽  
Dry Mass ◽  
Stem Diameter ◽  
N Content ◽  
N Concentration ◽  
The Mean ◽  
Number Of Seeds

To clarify how seed production depends on the relative N and dry mass availability, we examined the number and size of seeds, and the loss of dry mass in Cardiocrium cordatum (Thunb.) Makaino plants that differed naturally in overall size and stem N content. After adjusting for plant size (basal stem diameter was used as a criterion of plant size), the amount of dry mass lost because of respiration in a plant decreased with an increase in the stem N content of the plant, whereas the total dry mass of seeds of a plant increased with an increase in the stem N content. Plants with a high stem N content relative to dry mass status used dry mass resources more efficiently in seed production by reducing the loss of dry mass. Plants with a higher stem N content produced a greater number of seeds, and the amount of dry mass lost decreased with an increase in the number of seeds of the plant, possibly because the resources allocated to seed production are consumed rapidly, if numerous seeds simultaneously absorb those resources. However, the stem N content of a plant had no influence on the mean seed dry mass, seed N content, and the seed N concentration, and the latter three parameters did not affect respiration loss of dry mass. We concluded that plants undergoing seed production reduce dry mass loss if their relative N to dry mass availability is high, through an increase in the numbers of seeds they produce.

The effect of defoliation on seed production by capeweed (Arctotheca calendula)

1973 ◽  
Vol 13 (65) ◽  
pp. 676 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Yield Components ◽  
Seed Weight ◽  
Leaf Removal ◽  
Late Flowering ◽  
Individual Seed ◽  
Number Of Seeds

Two experiments were done in pots to assess the effect of defoliation at different times on the seed yield of capeweed (Arctotheca calendula). Yield components measured were: number of seedheads per plant, number of seeds per seedhead, number of seeds per plant, and weight of individual seeds. Of the components of yield, number of florets per seedhead and individual seed weight were maintained under all treatments; number of seedheads and number of seeds per seedhead were more affected by defoliation. Whether grown as spaced plants or in swards, leaf removal did not significantly reduce the number of seeds produced unless combined with bud and flower removal at late flowering only. The results are discussed in relation to the growth and persistence of capeweed in pastures.

EFFECTS OF BRACHYPTEROLUS PULICARIUS (L.) (COLEOPTERA: NITIDULIDAE) ON FLOWERING AND SEED PRODUCTION OF COMMON TOADFLAX

1992 ◽  
Vol 124 (4) ◽  
pp. 631-636 ◽  
Author(s):  
A.S. McClay
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Shoot Biomass ◽  
Percentage Germination ◽  
Linaria Vulgaris ◽  
Potted Plants ◽  
Delayed Onset ◽  
Adult Feeding ◽  
Viable Seeds ◽  
Total Seed

AbstractImpact of the flower- and shoot-tip-feeding beetle, Brachypterolus pulicarius (L.), on growth, flowering, and seed production of common toadflax, Linaria vulgaris (L.) Mill., was investigated using potted plants. Brachypterolus pulicarius had no effect on root or shoot biomass of attacked plants. Adult feeding by B. pulicarius delayed onset of flowering by 27 days relative to controls. Flowering of attacked plants was suppressed from mid-June until mid-July, but by mid-August flowering was similar to that of control plants. Total seed weight, individual seed weight, and percentage germination were all reduced significantly on attacked plants, resulting in a 74% reduction in number of viable seeds produced. Brachypterolus pulicarius is univoltine in Alberta, overwintering mainly as pupae.

Mean performance, range and analysis of variance in Indian mustard (Brassica juncea L. Czern and Coss)

2019 ◽  
Vol 4 (01) ◽  
pp. 34-40
Author(s):  
Amit Tomar ◽  
Manish Kumar Srivastava ◽  
Mahak Singh
Keyword(s):  
Analysis Of Variance ◽  
Seed Yield ◽  
Seed Weight ◽  
Oil Content ◽  
Indian Mustard ◽  
Flower Number ◽  
Mean Values ◽  
Days To Maturity ◽  
The Mean ◽  
Number Of Seeds

The analysis of variance based on mean values of 10 characters namely, day to flower, number of primary branches per plant, number of secondary branches per plant, days to maturity, plant height (cm), number of siliquae per plant, number of seeds per siliquae, 1000-seed weight (g), oil content (%) and seed yield per plant (g) were studied for testing the significance of differences among the treatments. The mean sum of squares for all the characters. Highly significant differences were recorded among all the treatments for all the 10 characters except number of primary branches per plant, number of secondary branches per plant, days to maturity and oil content.

Variable paths to seed production within the Kangaroo Valley cultivar of Lolium perenne

1991 ◽  
Vol 42 (1) ◽  
pp. 151 ◽  
Author(s):  
SG Shah ◽  
CJ Pearson ◽  
AC Kirby
Keyword(s):  
Seed Production ◽  
Lolium Perenne ◽  
Seed Yield ◽  
Low Temperatures ◽  
Seed Weight ◽  
Floral Development ◽  
Dry Weight ◽  
Daily Rate ◽  
Spike Number ◽  
The Mean

Components of seed yield were measured in an erect, early-flowering biotype and a prostrate, late-flowering biotype of Lolium perenne cv. Kangaroo Valley at temperatures from 15/10 to 24/19�C (12/12 h day/night). We aimed to determine if each biotype had distinctive components of seed yield, and if these varied according to temperature. The two biotypes had distinctive paths to seed yield. Seed yield per plant in an erect biotype depended more on seed weight per spike and less on spike number than in a prostrate biotype. The distinctive paths to seed yield, and relative stability in paths across temperatures, indicated that it was possible to select genotypes from within the Kangaroo Valley cultivar which had particular correlations among components of yield. Floral development was accelerated, but seed yield per plant and most of its components were reduced, at high temperature; only the mean daily rate of dry weight accumulation by individual seeds was the same at all temperatures. At any temperature, seed weight per spike declined almost linearly with lateness of spike emergence within a plant: spikes which emerged within 21 days of the earliest spike contributed 80% of the seed yield per plant. We conclude that biotypes can be selected within the Kangaroo Valley cultivar to have distinctive components of seed yield and, based on the two biotypes we studied, commercial seed production should be based at a location having relatively low temperatures.

Seed production and dormancy in Rumex crispus. II. The effects of removal of various proportions of flowers at anthesis

1971 ◽  
Vol 49 (10) ◽  
pp. 1841-1848 ◽  
Author(s):  
M. A. Maun ◽  
P. B. Cavers
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Total Yield ◽  
Lower Portion ◽  
Rumex Crispus ◽  
Individual Seed ◽  
The Mean ◽  
Seeds And Fruits

Systematic removal of 25, 50, and 75% of the flower whorls from panicles of Rumex crispus L. (curled dock) reduced the total yield per panicle of seeds and fruits in comparison to control plants. However, the mean weight per seed was progressively higher as a greater proportion of the whorls was removed.For untreated plants, seeds borne toward the tips of branches were always lighter than those found near the junctions of branches with the main rachis. Seeds from the lower portion of the panicle were generally larger than those from the upper branches. On treated plants individual seed weight became less variable over the whole panicle.Although seeds from all treatments were equally viable, the larger seeds from treated plants exhibited a greater amount of dormancy under several germination regimes. This increased dormancy might be attributed to the thicker investing structures of larger seeds.

Dispersal of seeds of giant Sporobolus spp. after ingestion by grazing cattle

1995 ◽  
Vol 35 (3) ◽  
pp. 353 ◽  
Author(s):  
TS Andrews
Keyword(s):  
New South ◽  
Heavy Rain ◽  
North Coast ◽  
The North ◽  
Fresh Manure ◽  
Grazing Cattle ◽  
South Wales ◽  
Cattle Faeces ◽  
Viable Seeds ◽  
Number Of Seeds

Samples of fresh cattle faeces were taken from 2 grazing paddocks on the North Coast of New South Wales. One paddock was heavily infested with giant Parramatta grass (GPG, Sporobolus indicus var. major) and the other paddock had a medium-light infestation. Fifty-two and 14 viable GPG seeds/kg were recovered from the dung samples collected in May from these paddocks, respectively. Seeds of GPG and giant rat's tail grass (GRTG, S. pyramidalis) were fed to caged Friesian heifers in 2 experiments, and the time taken for all of the seeds to be excreted was measured: 4 days in experiment 1 and 7 days in experiment 2. Consequently, a 7-day withholding period is suggested for cattle grazing pastures infested with giant sporobolus. The number of viable seeds excreted was estimated as a proportion of seeds fed to each heifer using average viability of seeds recovered, concentration of viable seeds collected daily, and daily manure weights. Based on this, the number of seeds ingested by gazing stock was estimated to be 8300 and 2200 seeds/head.day for the paddocks with heavy and medium-light infestation, respectively. Manure collected 2 and 3 days after feeding had the highest concentrations of viable seeds. This manure was placed outdoors in styrofoam boxes and left for 7 months. No GPG seedlings or plants were present in the manure after this time, and further subsampling of the manure indicated that no viable seeds remained. Processes that disperse fresh manure, such as heavy rain or the hosing down of transport vehicles, may allow successful germination and emergence of giant sporobolus seeds. However, where dung pats are left intact for some months, establishment of giant sporobolus plants is unlikely. Adhesion to machinery and the hair of stock are likely to be more important causes of dispersal of giant sporobolus than ingestion by stock.

Effect of Shade on Velvetleaf (Abutilon theophrasti) Growth, Seed Production, and Dormancy

1995 ◽  
Vol 9 (3) ◽  
pp. 452-455 ◽  
Author(s):  
Iliya A. Bello ◽  
Micheal D. K. Owen ◽  
Harlene M. Hatterman-Valentp
Keyword(s):  
Plant Height ◽  
Seed Production ◽  
Seed Weight ◽  
Dry Weight ◽  
Growing Season ◽  
Abutilon Theophrasti ◽  
Leaf Number ◽  
Number Of Leaves ◽  
Number Of Seeds ◽  
Number Of Branches

Growth, seed production, and dormancy of velvetleaf in response to shading were evaluated in the field. Velvetleaf plant height, leaf number, number of branches, and plant dry weight decreased linearly with increasing shade. No differences were observed for plant height, number of leaves, or branches/plant when plants were shaded 30% or not shaded throughout the growing season. However, the 76% shade treatment reduced velvetleaf height (1984 only), leaf number, stem branches, and plant dry weight. These reductions were greater in 1984 than 1985 except for plant dry weight that decreased by 88% each year. The number of capsules and the number of seeds/plant decreased linearly with increasing shade levels, while the seed weight increased with increasing shade level. Shading also decreased seed dormancy. These results demonstrate that shade suppresses velvetleaf growth and seed production, and shortens the dormancy of seeds that are produced by these plants.

Sign in / Sign up

Export Citation Format

Share Document