scholarly journals Cone quality and seed efficiency in the clones from mutational witches brooms of Pinus sibirica

2018 ◽  
Vol 11 ◽  
pp. 00034
Author(s):  
Olga Polyakova ◽  
Evgeniya Zhuk ◽  
Sergei Goroshkevich
Keyword(s):  
Apical Meristem ◽  
Shoot Growth ◽  
Seed Quality ◽  
Pinus Sibirica ◽  
Normal Cones ◽  
Tree Crown ◽  
Normal Seed ◽  
Empty Seeds ◽  
Filled Seeds ◽  
Size And Structure

Mutational witches' broom is a fragment of the tree crown with abnormal morphogenesis including slow shoot growth, abundant branching and decreased apical dominance which caused by somatic mutation that presumably originates in the apical meristem bud. To study the variability in the cone quality and seed efficiency in witches' broom clones of Pinus sibirica, the cone size and structure were assessed in 21 mutant clones. The mutant clones were significantly differentiated both by the cone traits and seed quality. Their cone size varied from less than 3 to 4 cm. The clones had large number of sterile scales in proximal and distal cone parts, and from 16 to 39 fertile scales per cone. Cones from all mutant clones were inferior to average normal cones of the species. Six clones had large portion of filled seeds, more than 70%, and the other clones had less than 50% of filled seeds. The clones had 10-33% of empty seeds and 1-73% of seeds with collapsed megagametophyte per cone. In general, the seed quality in mutants was quite low, but individual clones had almost normal seed quality, and their seed efficiency was within the species norm.

scholarly journals Accelerated formation of Siberian pine (Pinus sibirica Du Tour) stands: a case study from Siberia

2019 ◽  
Vol 65 (No. 8) ◽  
pp. 291-300
Author(s):  
Nikita Debkov
Keyword(s):  
Seed Production ◽  
Threshold Value ◽  
Pinus Sibirica ◽  
Natural Conditions ◽  
Normal Seed ◽  
Pine Trees ◽  
Pinus Sibirica Du Tour ◽  
Siberian Pine ◽  
Production Dynamics

Under natural conditions, Siberian pine Pinus sibirica begins to produce commercial cone yields of nuts relatively late (after more than 100 years). The aim of this study was to summarise the experience of the directed formation of Siberian pine forests in Siberia. Experimental objects included plots with traditional thinning of varying intensity and frequency as well as chemical treatment. We assessed the parameters of the stand and its seed production dynamics. Only stands with a minimum density (395–435 trees·ha–1) had a normal seed production energy (1.5 or more cones per shoot). Over-dense stands (830–930 trees·ha–1) were characterised by a low seed production energy (two times or more below the threshold value). In all plots, there were Siberian pine trees with absent or unacceptable seed production energy, which should be removed (DBH up to 28 cm). Seed production energy positively correlated with most tree parameters (age, height, diameter, volume, length and width of crown).

GROWTH AND DEVELOPMENT OF THE LOWBUSH BLUEBERRY: APICAL ABORTION

1963 ◽  
Vol 41 (9) ◽  
pp. 1319-1324 ◽  
Author(s):  
W. G. Barker ◽  
W. B. Collins
Keyword(s):  
Vegetative Growth ◽  
Growth And Development ◽  
Apical Meristem ◽  
Shoot Growth ◽  
Strong Indication ◽  
Vegetative Tissue ◽  
Aerial Shoot ◽  
Lowbush Blueberry ◽  
Below Ground ◽  
High Level

The semicultivated lowbush blueberry is fire-pruned on a 3- to 4-year cycle. In spring, vegetative growth is accomplished through the development of an axillary bud on an aerial shoot. In a fire-pruned area, the growth is delayed in both its initiation and termination by as much as a month and arises either from axillary buds on the unburned below-ground portions of the aerial stems, or from rhizome seated buds. Shoot growth is terminated by the abortion of the apical meristem and the death of the proximal portions of the axis. Evidence is presented suggesting that the death of the apex is not triggered by an appropriate photoperiod. Further, although it is inherently controlled, it does not follow the production of a specified quantity (relative to clone) of leaf nor vegetative tissue and is not related to the development of a specified (per clone) leaf photosynthetic area. Finally, there is a strong indication that the death of the shoot is speeded by the presence of a high level of auxin.

scholarly journals Effect of frost injury on quality of flax seed

1994 ◽  
Vol 74 (2) ◽  
pp. 331-333 ◽  
Author(s):  
G. H. Gubbels ◽  
D. M. Bonner ◽  
E. O. Kenaschuk
Keyword(s):  
Linum Usitatissimum ◽  
Seed Quality ◽  
Frost Damage ◽  
Laboratory Studies ◽  
Flax Seed ◽  
Linum Usitatissimum L ◽  
Damage Seed ◽  
Frost Injury ◽  
Normal Seed

In field and laboratory studies, flax (Linum usitatissimum L.) was frozen when 40–60% of the capsules were still green. Seed visibly frozen at this stage were of lower weight and density, darker in color, and lower in germinabihty than the fraction of the sample that was not visibly frozen. Also, oil color was darker, oil and protein concentrations and stearic and oleic acid levels were lower, and palmitic, linoleic and linolenic acid levels and iodine values were higher in the frozen than the normal seed. Key words: Flax, Linum usitatissimum, frost damage, seed quality, germination

Regrowth response of young black spruce (Picea mariana) trees to meristem removal and resource addition

2003 ◽  
Vol 81 (9) ◽  
pp. 956-963 ◽  
Author(s):  
Marcy Bast ◽  
R J Reader
Keyword(s):  
Picea Mariana ◽  
Apical Dominance ◽  
Apical Meristem ◽  
Compensatory Growth ◽  
Shoot Growth ◽  
Black Spruce ◽  
Mineral Nutrients ◽  
Mineral Nutrient ◽  
Supply Condition ◽  
K Fertilizer

Regrowth of an injured plant may exceed the growth of a noninjured plant (i.e., overcompensation) when (i) dormant meristems are available to replace injured meristems, (ii) the injury level is sufficient to release dormant meristems from apical dominance, and (iii) the supply of mineral nutrient and light is sufficient to support the outgrowth of previously dormant meristems. A field experiment was conducted with 5-year-old black spruce trees to determine whether these three conditions were met when 25%, 50%, or 75% of a tree's uppermost buds were removed. Subsequent shoot growth on treated and nontreated trees (0% meristem removal) was compared for each of two levels of resource supply (natural and enhanced). Enhanced levels of light and mineral nutrients were created by removing neighbouring plants within a 2-m radius of a target tree and adding 10 grams of N–P–K fertilizer per tree. After 5 and 17 months, shoot growth did not differ significantly among trees in the four meristem removal treatments (condition ii above), regardless of resource supply (condition iii above). The absence of overcompensation most likely reflects the relatively small supply of dormant meristems on treated trees (condition i above).Key words: apical meristem, black spruce, compensatory growth, injury.

Seed and pollen production after stem injections of gibberellin A4/7 in field-grown seed orchards of Pinus sylvestris

1998 ◽  
Vol 28 (3) ◽  
pp. 340-346 ◽  
Author(s):  
Urban Eriksson ◽  
Gunnar Jansson ◽  
Curt Almqvist
Keyword(s):  
Pinus Sylvestris ◽  
Seed Production ◽  
Seed Weight ◽  
Floral Induction ◽  
Pollen Production ◽  
Seed Orchards ◽  
Cone Production ◽  
Empty Seeds ◽  
Filled Seeds

The effects of stem injections of gibberellin A4/7 (GA4/7) were studied in two experiments conducted in two different field-grown seed orchards of Pinus sylvestris L. Both experiments were carried out during years with favourable conditions for floral induction, i.e., higher temperatures and less precipitation than average years. In experiment 1, cone production and the number of filled seeds per graft increased significantly, the latter by about 60% compared with the control. Filled seeds per graft increased in experiment 2 as well, although the increase was not statistically significant. In both experiments, GA4/7 treatment significantly reduced the 1000-seed weight but did not significantly affect the number of filled and empty seeds per cone. In both experiments, grafts stimulated to increase seed production tended to produce smaller cones. In experiment 2, pollen production was significantly increased after stem injections of GA4/7. The increase above the control was about 90%. There was a tendency for stem injections of GA4/7, which were intended to increase seed production, to reduce pollen production. Clonal effects were significant for all variables tested in the study. No damage to the treated grafts were observed that could be attributed to the treatment. The use of stem injections of GA4/7 as an operational means in seed orchards of P. sylvestris is therefore recommended.

scholarly journals Growth and Reproductive Phenology of Welwitschia Mirabilis Hook. F.

2013 ◽  
Vol 7 (1) ◽  
pp. 39-46 ◽  
Author(s):  
M. Di Salvatore ◽  
A. M. Carafa ◽  
G. Carratù
Keyword(s):  
Reproductive Success ◽  
Reproductive Traits ◽  
Botanical Garden ◽  
Day Length ◽  
Reproductive Phenology ◽  
Embryo Abortion ◽  
Male And Female ◽  
Welwitschia Mirabilis ◽  
Empty Seeds ◽  
Filled Seeds

Reproductive phenology, reproductive traits and the pre emergent reproductive success (PERS) of Welwitschia mirabilis were studied in plants growing in the Botanical Garden of Portici. The leaves grow throughout the year and growth is positively correlated to temperature and day length; at flowering, the growth rate slows down. The plants have a reproductive cycle lasting 9-10 months; male plants form more branches and strobili than females, female strobili are larger than male ones. Both male and female plants produce cones that differ in the color of the covering bracts. Plants produce a lot of seeds, but most of them are empty; therefore the seed/ovule ratio is low. Filled and empty seeds are morphologically similar; filled seeds have high vitality that is maintained for several years. As probable causes of the low seed/ovule ratio, both pollination and embryo abortion are taken into account; our observations lead us to believe that the embryo abortion hypothesis is more accurate. However, since each plant may produce a discrete number of cones and filled seeds are highly viable, ultimately Welwitschia appears to be a rather efficient plant in terms of pre emergent reproductive success.

scholarly journals Increasing Tree Complexity and Bearing Potential in Young `Fuji' Apple Trees

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 506E-507
Author(s):  
Marius Huysamer
Keyword(s):  
South African ◽  
Apical Meristem ◽  
Shoot Growth ◽  
Block Designs ◽  
Leaf Removal ◽  
Apple Trees ◽  
The Third ◽  
Fuji Apple ◽  
Growing Conditions ◽  
Old Trees

Under typical South African growing conditions, `Fuji' apple (Malus domestica Borkh.) trees are characterized by strong apical dominance during the first few years after planting. This, together with the current lack of suitable precocious rootstocks and the tip-bearing habit, causes willowy “blind wood” growth with few flowering positions, and delays bearing until the third leaf when a crop of less than 10 tons/hectare can be realized. Promalin (GA4+7 and benzyladenine, Abbott Laboratories) was used in combination with apical meristem defoliation and Agral or Armoblen as surfactant/penetrant to induce sylleptic shoot growth in an effort to increase tree complexity (i.e., branching) without having to resort to pruning, which is dwarfing and delays bearing. The treatments were tested on `Fuji' grafts, 1-year old trees and 2-year old trees in the 1993–1994, 1994–1995, and 1995–1996 seasons, respectively. Concentrations tested were 0, 500, 750, or 1000 ppm, as single or multiple applications in spring. In all trials, randomized, complete block designs were used. Control trees had few, if any, sylleptic shoots or spurs, whereas Promalin in combination with leaf removal or in combination with Armoblen caused significant sylleptic growth to occur. Generally, multiple applications spaced fortnightly, gave best results. Sylleptic shoots were ≈15 cm long, terminated in a reproductive bud, and did not influence the length of the “mother” shoot or the trunk circumference. Based on these results, a combination of multiple applications of 500 ppm Promalin with Armoblen as penetrant, and no leaf removal, is being tested semi-commercially this season.

scholarly journals Pollenizer and Cultivar Influence Seed Number and Fruit Characteristics in Olea europaea L.

HortScience ◽  
2012 ◽  
Vol 47 (10) ◽  
pp. 1430-1437 ◽  
Author(s):  
Daniela Farinelli ◽  
Pierluigi Pierantozzi ◽  
Assunta Maria Palese
Keyword(s):  
Seed Quality ◽  
Seedling Survival ◽  
Central Italy ◽  
Fruit Weight ◽  
Seed Number ◽  
Fruit Characteristics ◽  
Final Weight ◽  
Normal Seed ◽  
Olive Cultivars ◽  
Dispersal Unit

The effect of several pollination combinations of the olive cultivars Ascolana Tenera, Carolea, Leccino, and Picholine on seed quality and seed number and drupe and seed features were evaluated in 2007 and in 2008 in central Italy. The well-known pattern in olive fruit was confirmed by the high percentage of drupes (71.8%, on average) containing one seed with a closed endocarp, as the dispersal unit, optimizing the plant’s investment in seedling survival. Based on the results of the χ2 test of independence, there was a significant maternal and paternal effect on the number of normal seeds per drupe in some years and combinations. Particularly, in 2007, Picholine and Leccino cultivars (as mother) had drupes with two normal seeds (23.7% and 3.1%, respectively, with respect to 10.8% observed in a normal seed pattern), confirming that double-seeding in olive could be cultivar-dependent. Also the specific crosspollination between ‘Carolea’, as a pollenizer, and ‘Ascolana Tenera’ gave rise to a higher proportion of double-seeded drupes in 2007 (39% with respect to 14.3% expected to be in this category). In 2008, although ‘Ascolana Tenera’ produced more drupes with undeveloped seeds (31.9% with respect to 19.7% expected to be in that category), ‘Leccino’ and ‘Carolea’ had drupes with a lower number of undeveloped seed (14.2% and 11.5%, respectively). ‘Maurino’ and ‘Ascolana Tenera’ pollen produced significant effects on ‘Leccino’ drupes by increasing the number of drupes with undeveloped seeds in both experimental years. Double-seeded drupes outweighed those with only one normal seed in ‘Leccino’ and ‘Picholine’. Instead, drupes with undeveloped seeds affected fruit weight, being generally lighter than those with normal seeds. Although the Leccino cultivar, combined with ‘Maurino’ and ‘Ascolana Tenera’, greatly increased the proportion of drupes without normal seed, such condition did not affect their final weight, which was not different from those with one normal seed, suggesting that this variety caused late seed death.

scholarly journals Crossability of Pinus sibirica and P. pumila with their hybrids

2013 ◽  
Vol 62 (1-6) ◽  
pp. 61-67 ◽  
Author(s):  
G. V. VasilyevA ◽  
S. N. Goroshkevich
Keyword(s):  
Seed Production ◽  
Parental Species ◽  
First Year ◽  
Pinus Sibirica ◽  
Hybrid Seed Production ◽  
Female Cone ◽  
Field Station ◽  
Cone Development ◽  
Pollen Distribution ◽  
Filled Seeds

AbstractCrossability of Pinus sibirica and P. pumila hybrids and their parental species was studied using the controlled pollination method. Pinus sibirica and its hybrids were represented by grafts at the “Kedr” field station southeast of Tomsk Oblast, Russia; the parental species was of local provenance, with its hybrids obtained from the Southern Baikal region. In the case of P. pumila, trees were pollinated in a wild stand located in the Upper Angara River delta. Parental species had the highest number of filled seeds under open pollination. When they were pollinated with hybrid pollen, the trees showed nearly two-fold reductions in the number of filled seeds. Hybrids tended to abort most ovules during the first year of female cone development, resulting in a high seed abortion rate and consequent low seed production. The number of filled seeds obtained from hybrids was low, with levels ranging from 8.2 to 24.3%. Because of weak reproductive isolation between hybrids and parental species, crosses are inevitable and lead to species introgression. The hybrids probably contribute to interspecies genetic exchange both through hybrid seed production following pollination by parental species and by hybrid pollen distribution.

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