scholarly journals Differential interspecific incompatibility among Populus hybrids in sections Aigeiros Duby and Tacamahaca Spach

2011 ◽  
Vol 87 (06) ◽  
pp. 790-796 ◽  
Author(s):  
A. Assibi Mahama ◽  
Richard Hall ◽  
Ronald Zalesny
Keyword(s):  
Success Rate ◽  
Seed Production ◽  
Interspecific Hybrids ◽  
Seed Set ◽  
Interspecific Crosses ◽  
Interspecific Incompatibility

In our previous Populus breeding, compatible crosses between P. maximowiczii A. Henry and P. deltoides Bartr. ex Marsh corroborated the potential of interspecific hybrids, despite low seed set. Our current objective was to test the range of incompatibility among intraspecific and interspecific crosses using parental germplasm from the sections Aigeiros Duby (P. deltoides and P. nigra L.) and Tacamahaca Spach (P. maximowiczii). We determined the success rate of crosses, along with seed production and seedling viability. The success of crosses ranged from complete incompatibility to complete compatibility, with 29% to 85% of the transplanted germinants developing into healthy seedlings.

scholarly journals Production of Interspecific Hybrids between Hexaploid Fragaria moschata and the diploid species F. nubicola and F. viridis.

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 610b-610
Author(s):  
Robert H. Bors ◽  
J. Alan Sullivan
Keyword(s):  
Seed Germination ◽  
Ploidy Level ◽  
Interspecific Hybrids ◽  
Leaf Morphology ◽  
Seed Set ◽  
Embryo Rescue ◽  
Diploid Species ◽  
Interspecific Crosses ◽  
Good Seed ◽  
Poor Seed

Interspecific crosses with Fragaria moschata (6x) have been hampered by ploidy level differences, poor seed set, and extremely poor seed germination. Modification of pollination practices, embryo rescue, and use of several genotypes has allowed over 80 synthetic tetraploids to be created from 14 cross combinations. Germplasm for the experiment consisted of eight selections of F. moschata (6x), two of F. nubicola (2x), and two of F. viridis (2x). Both 2x × 6x and 6x × 2x crosses were performed. Initially, negligible seed set occurred on F. nubicola and F. viridis when multiple flowers per truss were pollinated. When only one cross was performed per truss, with other flowers removed, seed set was greatly enhanced. F. moschata was much more tolerant of multiple crosses per truss. The crossing combination of F. moschata × F. nubicola gave the worst seed production. Other species combinations were capable of producing good seed set with noticeable differences between individual selections. When achenes were halved, only 1% appeared normal, 2% were underdeveloped or shrunken, the remainder were empty. Many of the malformed and most of the normal embryos germinated using the cut achene method. Achenes were surface-sterilized, cut in half, and placed on MS media with activated charcoal (3g·L–1), sucrose (30g·L–1), and no hormones. Germination occurred only from achenes from fully ripened fruit. Viable hybrids were obtained from 2x × 6x as well as 6x × 2x crosses. Fragaria viridis–F. moschata hybrids closely resembled F. moschata while F. nubicola–F. moschata hybrids were more intermediate in leaf morphology.

scholarly journals REPRODUCTIVE EXPRESSION OF GENETIC INCONGRUITY IN Fl PROGENY OF INTERSPECIFIC CROSSES OF VITIS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 601d-601
Author(s):  
Debbv M. Filler ◽  
James J. Luby ◽  
Peter D. Ascher
Keyword(s):  
Analysis Of Variance ◽  
Interspecific Hybrids ◽  
Fruit Set ◽  
Seed Set ◽  
Interspecific Crosses ◽  
Class Iii ◽  
Breeding Programs ◽  
Sib Families ◽  
Selection For ◽  
Fruit And Seed Set

Three classes of crosses using four genotypes of V. riparia (wild Riverbank grape) as maternal parents were evaluated for evidence of reproductive expression of genetic incongruity. The classes were: I V. riparia x V. vinifera cultivars (European domesticated grape); II V. riparia x French Hybrids (complex interspecific hybrids); III V. riparia x V. riparia. Percent fruit set and seeds per berry were recorded for two years. If incongruity is a factor in interspecific grape crosses, then the values for these traits would be expected to be lower in classes I and II than in class III. Analysis of variance indicated significant differences for some half-sib families. Fruit and seed set were lower in classes I and II than in class III, suggesting that incongruity is operative in wide grape crosses. In the process of creating French hybrids, genomes of several species came together over generations of hybridization. In concert with selection for fertility, repeated interspecific genomic exposure would be expected to have ameliorated the effects of initial incongruity between American species and V. vinifera, increasing their value as genetic bridges in breeding programs.

Early events in the embryo sac after intraspecific and interspecific pollinations in Rhododendron kawakamii and R. retusum

1986 ◽  
Vol 64 (2) ◽  
pp. 282-291 ◽  
Author(s):  
V. Kaul ◽  
J. L. Rouse ◽  
E. G. Williams
Keyword(s):  
Seed Set ◽  
Embryo Sac ◽  
Pollen Tubes ◽  
Interspecific Crosses ◽  
Primary Endosperm Nucleus ◽  
Kalmia Latifolia ◽  
Taxonomic Grouping ◽  
Similarities And Differences ◽  
Normal Fertilization

Early events in the embryo sac of Rhododendron kawakamii and R. retusum have been studied after compatible self-pollinations and eight interspecific crosses, using sectioned ovaries, pistil squashes, and seed-set data. Ovules of Rhododendron kawakamii and R. retusum are anatropous, unitegmic, and tenuinucellate, with a typical eight-nucleate, seven-celled embryo sac. Fertilization normally occurs 4–5 days after pollination. The zygote lays down a callose wall but remains undivided during the first 13–15 days after pollination. The primary endosperm nucleus divides soon after fertilization, and development is cellular ab initio. Crosses of R. kawakamii (♂) with R. santapaui and R. retusum and crosses of R. retusum (♂) with R. kawakamii, R. santapaui, R. ovatum, and R. tashiroi showed apparently normal fertilization in a majority of ovules entered by pollen tubes. In crosses of R. kawakamii (♂) with R. quadrasianum and Kalmia latifolia entry of pollen tubes into ovules was delayed and frequently abnormal. Apart from compatible self-pollinations of R. kawakamii an R. retusum, only the cross of R. kawakamii (♂) with R. santapaui produced healthy seedlings. Of the remaining seven interspecific crosses only three showed significant embryo development in control pistils left to mature in situ. Similarities and differences in the breeding behaviour of R. kawakamii and R. retusum are discussed with reference to their taxonomic grouping within subsection Pseudovireya.

Unilateral incompatibility and the effects of interspecific pollination for Erythronium americanum and Erythronium albidum (Liliaceae)

1993 ◽  
Vol 71 (2) ◽  
pp. 353-358 ◽  
Author(s):  
Lawrence D. Harder ◽  
Mitchell B. Cruzan ◽  
James D. Thomson
Keyword(s):  
Seed Production ◽  
Pollen Tubes ◽  
The Self ◽  
Pollen Transfer ◽  
Interspecific Incompatibility ◽  
Unilateral Incompatibility ◽  
Heterospecific Pollen ◽  
Interspecific Pollen Transfer ◽  
Erythronium Americanum ◽  
Incompatibility Reaction

To determine whether interspecific pollen transfer could reduce seed production by two sympatric lilies, Erythronium albidum and Erythronium americanum, we hand-pollinated flowers with mixtures of conspecific and heterospecific pollen. These species exhibited typical unilateral interspecific incompatibility, i.e., pollen tubes from the self-infertile species (E. americanum) grew apparently unimpeded in styles of the self-fertile species (E. albidum), whereas the reverse cross resulted in an incompatibility reaction. Because of this asymmetrical relation and faster growth by heterospecific pollen tubes in E. albidum stigmas than by conspecific tubes, pollination with abundant heterospecific pollen reduced fruit and seed production by E. albidum, but not by E. americanum, as long as the stigma also received some conspecific pollen. Unilateral incompatibility could benefit self-infertile species in reproductive interactions with closely related self-fertile species; however, this benefit remains to be demonstrated for naturally pollinated plants. Key words: Erythronium albidum, Erythronium americanum, interspecific pollen transfer, pollination, unilateral incompatibility.

scholarly journals Inheritance and Linkage Relationships of Isozymes in Easter Cactus

1998 ◽  
Vol 123 (1) ◽  
pp. 98-103
Author(s):  
Maureen C. O'Leary ◽  
Thomas H. Boyle
Keyword(s):  
Interspecific Hybrids ◽  
Triosephosphate Isomerase ◽  
Recombination Frequency ◽  
Polyacrylamide Gel Electrophoresis ◽  
Interspecific Crosses ◽  
Germplasm Collections ◽  
Segregation Ratios ◽  
Isozyme Loci ◽  
Linkage Relationships ◽  
Aberrant Segregation

Polyacrylamide gel electrophoresis was used to study inheritance and linkage of isozymes in Easter cactus (Hatiora species and interspecific hybrids). Five isozyme systems were analyzed: aspartate aminotransferase (AAT), glucose-6-phosphate isomerase (GPI), malate dehydrogenase (MDH), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI). F1, F2, BC1, and S1 progeny were used for inheritance studies. Six polymorphic loci (Aat-1, Gpi-1, Mdh-1, Pgm-1, Pgm-2, and Tpi-2) were identified. Aat-1 and Pgm-1 were linked (recombination frequency = 26% ± 7%), but the other isozyme loci assorted independently. Aberrant segregation ratios were observed in at least one segregating family for all six isozyme loci. We hypothesize that segregation distortion was due to linkage between isozyme loci and other genes subject to pre- or postzygotic selection. The existence of five additional isozyme loci (Aat-2, Gpi-2, Mdh-2, Mdh-3, and Tpi-1) was inferred from segregation patterns and by comparison of isozyme profiles from phylloclades and pollen. These isozyme loci may prove useful for confirming hybridity in intra- and interspecific crosses, determining parentage of cultivars, and assessing genetic diversity in germplasm collections.

INTERSPECIFIC HYBRIDS INVOLVING ALFALFA. VI. INEFFECTIVENESS OF ALLOPLOIDY IN INDUCTION FERTILITY IN MEDICAGO PIRONAE × M. DAGHESTANICA HYBRIDS

1971 ◽  
Vol 13 (3) ◽  
pp. 437-442 ◽  
Author(s):  
K. Lesins
Keyword(s):  
Interspecific Hybrids ◽  
Seed Set ◽  
Interspecific Cross ◽  
Pollen Grains ◽  
Colchicine Treatment ◽  
Plant Meiosis

Colchicine treatment of hybrids from the interspecific cross Medicago pironae Vis. × M. daghestanica Rupr. induced the formation of three tetraploid shoots, one with 2n = 29 and two with 2n = 32, in their somatic nuclei. Their flowers had 21, 44 and 62% plasma-filled pollen, respectively. No seed was obtained from these tetraploids after selfing and intercrossing more than 1,200 flowers, indicating the presence of a built-in fertility barrier between the two species.By applying pollen from the tetraploid hybrids to alfalfa (M. sativn L.) two trispecies hybrids with 2n = 34 and 30 chromosomcs were produced. The first had 32%, the second 22% plasma-filled pollen grains. On backcrossing to M. sativa, a higher seed set was obtained with pollen from the 2n = 34 plant than from the 2n = 30 plant. Meiosis in the 2n = 30 plant was abnormal. At MI multivalents were observed, indicating that chromosomal material may be interchanged between M. pironae-daghestanica and M. sativa. Approximately half the meiocytes at AI possessed lagging chromosomes and only 6% of secondary meiocytes at AII were without disturbances.

Effect of companion perennial grasses and lucerne on seed yield and regeneration of subterranean clover in two wheatbelt environments

2001 ◽  
Vol 52 (10) ◽  
pp. 973 ◽  
Author(s):  
B. S. Dear ◽  
J. M. Virgona ◽  
G. A. Sandral ◽  
A. D. Swan ◽  
B. A. Orchard
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Bank ◽  
Seed Set ◽  
Subterranean Clover ◽  
Seedling Regeneration ◽  
Early Autumn ◽  
Background Population ◽  
Seed Reserves ◽  
Clover Seed

Seed production of subterranean clover (Trifolium subterraneum L.) in mixtures with lovegrass (Eragrostis curvula (Schrader) Nees cv. Consol), cocksfoot (Dactylis glomerata L. cv. Currie), phalaris (Phalaris aquatica L. cv. Sirolan), danthonia (Austrodanthonia richardsonii (Cashm.) H.P. Linder, cv. Taranna), and lucerne (Medicago sativa L. cv. Aquarius) was compared with pure and degraded (invaded by annual volunteers) annual subterranean clover pasture at 2 sites (Junee and Kamarah) in the southern wheatbelt of New South Wales. Seed yields, clover seedlings in winter, and the change in the proportion of 3 subterranean clover cultivars (Dalkeith, Seaton Park, Goulburn) when grown with and without perennials were assessed. The effect of thinning the perennials to 10 plants/m2 on clover seed set was examined at the drier site. Seed production of subterranean clover in the mixtures was depressed by up to 50% compared with the pure and degraded annual swards. Initial clover seed poduction in the mixtures was at least 60 kg/ha even in the drought year at the wetter site (Junee), and >85 kg/ha at Kamarah, the drier site (seedling establishment at Kamarah failed in the drought year). Clover seed reserves in the following 2 years progressively increased to >300 kg/ha in the perennial swards at Junee but were <100 kg/ha by the end of the third year at Kamarah. In comparison, seed reserves in the pure clover and degraded annual swards were >650 kg/ha at Junee and >350 kg/ha at Kamarah. Reducing perennial density to 10 plants/m2 at the drier site increased clover seed yield about 3-fold in the first year compared with unthinned perennial swards. The increased seed yield was due to increased numbers of burrs set and increased seeds per burr and, in all perennial pasture treatments except lucerne, increased seed size. Clover seedling regeneration in 3rd and 4th year after sowing was substantially lower in the perennial-based mixtures than annual plots, with a significant (P < 0.05) positive correlation at both sites between clover seedling regeneration and seed bank size (1996, r2 = 0.46–0.64; 1997, r2 = 0.64–0.85). Following false breaks in early autumn, clover seedling populations were substantially higher in the pure and degraded clover treatments than in most perennial treatments. The proportion of the 3 cultivars present in the seed bank at the end of the pasture phase differed between sites but the sward type only influenced the proportion at the drier site. At the medium rainfall site, the later maturing cultivar Goulburn constituted 27–54% of the seed bank and the early flowering Dalkeith 25–46%, with unsown cultivars being insignificant ( <1%). At the low rainfall site, Dalkeith was the major component (33–52%) of the seed bank but the background population of unsown cultivars constituted 11–48%, the lowest proportion being in swards without a perennial component. The proportion of Goulburn was highest (23%) in the pure sward and lowest (10%) in lucerne and phalaris. It was concluded that subterranean clover could form relatively stable mixtures with perennials in medium rainfall environments, with clover populations increasing with time. In lower rainfall environments, clover seedling populations in perennial swards may be low due to reduced seed set and decreased seedling survival following early autumn rains. In these environments earlier maturing, hard-seeded cultivars are more likely to persist in mixtures and there is more potential for unsown cultivars to constitute a greater proportion of the sward. Decreasing perennial density offers scope for improving clover seed set and survival in these environments.

The effects of frequency and extent of defoliation, summer irrigation, and fertilizer on the production and survival of the grass Danthonia caespitosa Gaud

1976 ◽  
Vol 27 (6) ◽  
pp. 755 ◽  
Author(s):  
KC Hodgkinson
Keyword(s):  
Seed Production ◽  
Death Rate ◽  
Field Experiments ◽  
Seed Set ◽  
Floral Induction ◽  
Early Winter ◽  
Phosphorus Fertilizer ◽  
Nitrogen And Phosphorus ◽  
Plant Survival ◽  
Growth And Survival

The effects of extent and frequency of defoliation on the growth and survival of Danthonia caespitosa were measured in a series of field experiments. Additional treatments, of summer irrigation and application of nitrogen and phosphorus fertilizer, were included in some of the experiments to assess how they modified the effects of defoliation. During the summer, complete defoliation increased the shoot yield of plants which had not been irrigated, but yield was decreased in the irrigated treatments. Frequent, partial defoliation increased yields of irrigated plants but decreased yields of plants not irrigated. Depression of yields was caused by both tiller death and reduced regrowth of individual tillers. In an experiment lasting 2 years, plants were completely defoliated monthly, bimonthly or tri-monthly or left intact, and shoot yields, tillering characteristics and plant survival under the treatments were compared. Monthly defoliation depressed yields and rate of tillering and accelerated the death rate of plants, particularly during the summer and autumn periods. Plants also died when cut bimonthly but the rate was slower. Plants irrigated during the first summer generally died at a faster rate than plants not irrigated. Tillering was more rapid during the autumn and early winter months. Midwinter application of fertilizer to plants cut bimonthly greatly stimulated shoot yields and seed production in the spring but not in the following year. Examination of tiller apices showed that floral induction took place prior to the beginning of July. Many apices were elevated above the 'grazing level' by early September, and flowering and seed set occurred in October.

Increased seed production of subterranean clover pastures in response to fertilizers supplying calcium

1974 ◽  
Vol 14 (71) ◽  
pp. 749 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Seed Production ◽  
Calcium Concentration ◽  
Field Experiments ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Unit Weight ◽  
Gypsum Plaster ◽  
Total Seed ◽  
Seed Yields

The effects of four common fertilizers containing calcium on seed production in subterranean clover (Trifolium subterraneum) were measured at six locations over five years in a total of fifteen field experiments. Calcium as a sulphate, carbonate or phosphate salt was applied to subterranean clover pastures either at the start of the growing season (autumn) or at flowering (spring). Gypsum, plaster of Paris, or lime gave large increases in seed yield per unit area and also per unit weight of tops. Spring applications of superphosphate increased seed yields in only two out of four experiments. Gypsum applied in spring at 200-500 kg ha-1 was as effective as 2,000 kg ha-1 of lime applied in autumn. Applications of lime in spring were much less effective. Increased seed yields were due to increases in burr yield, seed number per burr, and mean weight per seed. They were usually accompanied by increases in calcium concentration in the seed. Responses in seed production to calcium applications were obtained in all three sub-species of Trifolium subterraneum. In two experiments, newly sown on a soil type on which subterranean clover regeneration and persistence is commonly very poor, applied calcium doubled or quadrupled seed set. In 13 experiments using soils on which subterranean clover had persisted as the major component of the pasture for several years, calcium in the year of application increased the total seed bank by 6 to 31 per cent, and the current seed set by a greater amount.

Inheritance of mitochondrial DNA in interspecific crosses of Piceaglauca and Piceaomorika

1996 ◽  
Vol 26 (3) ◽  
pp. 428-432 ◽  
Author(s):  
Andrew J. David ◽  
Daniel E. Keathley
Keyword(s):  
Mitochondrial Dna ◽  
Interspecific Hybrids ◽  
Maternal Inheritance ◽  
White Spruce ◽  
Mitochondrial Genes ◽  
Interspecific Crosses ◽  
Length Polymorphisms ◽  
Dna Restriction ◽  
Total Dna ◽  
Serbian Spruce

Fifteen interspecific hybrids of Serbian spruce (Piceaomorika (Panc) Purkyne) and white spruce (Piceaglauca (Moench) Voss) representing five separate crosses, including reciprocals, were used to demonstrate maternal inheritance of mitochondrial DNA. Total DNA was extracted from foliage samples of Serbian spruce (S), white spruce (W), and both S(♂) × W(♀) and W(♂) × S(♀) hybrids, digested and probed with one of two maize mitochondrial genes, ATPaseα or COXII. ATPaseα generated diagnostic Serbian and white spruce genotypes for all five enzymes tested, while COXII differentiated between the two species for four of five enzymes. Maternal inheritance was indicated in all hybrids for every diagnostic enzyme–probe combination. No paternal or nonparental bands were detected. A dilution experiment indicated that the Serbian and white spruce mitochondrial DNA restriction fragment length polymorphisms could be detected in as little as 60 and 500 ng of total DNA, respectively. It appears that the mechanism that controls the inheritance of mitochondria in Picea is still functional in wide interspecific crosses.

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