Evidence for the existence of endosperm balance number in the true clovers (Trifolium spp.)

1986 ◽  
Vol 28 (4) ◽  
pp. 581-586 ◽  
Author(s):  
W. A. Parrott ◽  
R. R. Smith
Keyword(s):  
Ploidy Level ◽  
Related Species ◽  
Interspecific Hybrids ◽  
2N Gametes ◽  
Endosperm Development ◽  
Individual Species ◽  
Interspecific Crosses ◽  
Endosperm Balance Number ◽  
Endosperm Tissue ◽  
2N Eggs

The endosperm balance number (EBN) hypothesis was first advanced to explain results from interspecific crosses in Solanum and later in Impatiens. According to the EBN hypothesis, normal endosperm development following intra- or inter-specific crosses depends on having a ratio of two EBNs from the female to one EBN from the male in the endosperm tissue. EBNs may differ among related species. Successful hybrids can be obtained between species with the same EBN. The ploidy level of an individual species can be varied to modify its EBN, making it cross compatible with a species sharing its modified EBN. Interspecific crosses within Trifolium have been limited and difficult. Crosses reported in the literature, including evidence from our own study, suggest that EBN is operating in Trifolium and have been used to assign EBN numbers to some clover species. The use of 2n eggs enabled two species, differing in EBN, to be crossed. An understanding of the EBN mechanism that operates in Trifolium should make successful interspecific hybrids easier to obtain in the future.Key words: endosperm balance number, hybrids (interspecific), 2n gametes, Trifolium.

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.

Introgression of Solarium acaule germ plasm from the endosperm balance number 2 gene pool into the cultivated endosperm balance number 4 potato gene pool via triplandroids

Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 273-278 ◽  
Author(s):  
C. R. Brown ◽  
K. Adiwilaga
Keyword(s):  
Gene Pool ◽  
Interspecific Hybrids ◽  
Germ Plasm ◽  
Interspecific Crosses ◽  
Endosperm Balance Number ◽  
2N Pollen ◽  
Stainable Pollen ◽  
Low Frequencies ◽  
Pollen Formation ◽  
Cytological Mechanism

Triploid plants from interspecific crosses between selected clones of Solanum acaule and a 2n pollen producing, cultivated diploid expressed an average of 7.7% to 2n pollen, called triplandroids. Percent stainable pollen of these triploids ranged from 1.8 to 22.1%. The cytological mechanism of 2n pollen formation was parallel orientation of spindles in the second division of meiosis. Three triplandroid-producing triploids were crossed to several tetraploid potato cultivars and breeding clones. Of these 4x−3x pollinations, 49% produced berries, containing an average of 15.2 seeds. Progeny from 4x−3x crosses were 67% pentaploid, 2n = 60, and 33% aneuploids 2n = 56–59, mostly 2n = 59. Thus, functional microspores from triploids were predominantly triplandroids, 2n = 3x = 36, with low frequencies of aneuploidy. This use of a triplandroid bridge is a rapid means of introducing S. acaule germ plasm to the cultivated tetraploid gene pool.Key words: interspecific hybrids, parallel spindles, pollen restitution, triploidy, 2n pollen.

Reproductive Efficiency in Reciprocal Crosses of Arachis monticola with A. hypogaea Subspecies1

1998 ◽  
Vol 25 (1) ◽  
pp. 7-12 ◽  
Author(s):  
H. E. Pattee ◽  
H. T. Stalker ◽  
F. G. Giesbrecht
Keyword(s):  
New Mexico ◽  
Ploidy Level ◽  
Interspecific Hybrids ◽  
Female Parent ◽  
Reproductive Development ◽  
Interspecific Crosses ◽  
Reproductive Efficiency ◽  
Embryo Abortion ◽  
Reciprocal Crosses ◽  
Cultivated Peanut

Abstract Wild species of Arachis encompass a large number of species which can provide valuable genetic resources for improving A. hypogaea L., the domesticated peanut. Arachis monticola Krapov. and Rig. is the only species which is both cross compatible with A. hypogaea and at the same ploidy level. An evaluation of reproductive efficiency in crosses between A. hypogaea and A. monticola was conducted to better understand the potential for utilization of this germplasm. This study documents the reproductive efficiency of A. monticola in reciprocal crosses with A. hypogaea subsp. hypogaea var. hypogaea cvs. Florunner and NC 6; A. hypogaea subsp. fastigiata var. vulgaris cv. Argentine; and A. hypogaea subsp. fastigiata var. fastigiata cv. New Mexico Valencia C by using selfs as controls. A significant maternal effect was observed among selfs and hybrids for timing of fertilization. Selfs of Florunner and New Mexico Valencia C initiated fertilization by 1 d after pollination, whereas syngamy did not occur in selfs of NC 6, Argentine or A. monticola until after day 1. Fertilization approached 100% in A. monticola and A. hypogaea genotypes except for New Mexico Valencia C, which only had 70% of the eggs fertilized. Embryo abortion was observed in both selfs and interspecific hybrids, with the highest rates in selfs after the pegs entered the soil; but in hybrids abortion also occurred as the peg elongated. Crosses were generally more successful when A. hypogaea was the female parent, and developing cultivars with A. monticola cytoplasm will be difficult. Sixty to more than 90% of growing ovules aborted in different interspecific crosses. Arachis monticola selfs and hybrids most closely followed the pattern of reproductive development of A. hypogaea cv. Argentine, which lends support to the theory that A. monticola is a weedy derivative of the cultivated peanut.

Use of half-tetrad analysis to discriminate between two types of 2n egg formation in a potato haploid

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Joanna E. Werner ◽  
David S. Douches ◽  
Rosanna Freyre
Keyword(s):  
Solanum Tuberosum L ◽  
2N Gametes ◽  
Breeding Value ◽  
Tetrad Analysis ◽  
Recombination Rates ◽  
First Division Restitution ◽  
Egg Formation ◽  
Second Division Restitution ◽  
2N Eggs ◽  
Tetraploid Progeny

The ratio of the first division restitution (FDR) to second division restitution (SDR) 2n eggs was estimated in 4182t, a haploid (2n = 2x = 24) of Solanum tuberosum L. that produces 2n eggs by the two modes. The segregation of three genes previously mapped relative to their centromeres, Pgm-2 (2.0 cM), Mdh-1 (33.5 cM), and 6-Pgdh-3 (30.1 cM) was analyzed in the tetraploid offspring of a 2x × 4x cross. Based on the segregation of the Pgm-2 locus, 39.7% of the progeny originated from FDR 2n eggs and 60.3% from SDR. Segregation patterns of the two distal loci within the FDR-derived 4x subpopulation indicated that the gene–centromere recombination rate during megasporogenesis was significantly reduced for Mdh-1 when compared with a previous estimate during microsporogenesis. In the SDR-derived 4x subpopulation, the gene–centromere recombination rates for Mdh-1 and 6-Pgdh-3 were not significantly different from previous estimates. Tetraploid progeny generated from one 2x × 4x cross where the 2x parent produces 2n gametes by two modes can be used to make an unbiased comparison of the potential breeding value of FDR and SDR gametes.Key words: potato, megasporogenesis, first division restitution, second division restitution, isozyme.

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.

scholarly journals Ploidy Levels of Hardy Actinidia Accessions in the U.S. Determined by Flow Cytometry

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 439D-439 ◽  
Author(s):  
Mary Ann Start ◽  
James Luby ◽  
Robert Guthrie ◽  
Debby Filler
Keyword(s):  
Flow Cytometry ◽  
Ploidy Level ◽  
Interspecific Variation ◽  
Root Tip ◽  
Interspecific Crosses ◽  
Ploidy Levels ◽  
Haploid Chromosome Number ◽  
Tip Cells ◽  
Root Tip Cells ◽  
The U.S

The hardy Actinidia species represent a source of genetic diversity for improving A. deliciosa (kiwifruit) as well as for creating new economically important cultivars through intra- and interspecific crosses. Attempts at breeding in Actinidia have been complicated by the existence of intraspecific as well as interspecific variation in ploidy. The haploid chromosome number in Actinidia is 29 and diploid (2n=2x=58), tetraploid (2n=4x=116), and hexaploid (2n=6x=174) levels have been identified. Because of the problems encountered when crossing parents differing in ploidy level, it is desirable to know the ploidy levels of plants to be used in breeding. We determined the ploidy levels of 61 Actinidia accessions currently available in the U.S., including primarily accessions of relatively winter-hardy species. The 61 accessions, representing eight species and three interspecific hybrids, were screened for ploidy using flow cytometry. Mitotic root tip cells from one plant from each putative ploidy level were examined microscopically to confirm the ploidy level derived from flow cytometry. There were 17 diploids, 40 tetraploids, and 4 hexaploids. Intraspecific variation was not found among accessions of the species arguta, callosa, deliciosa, kolomikta, melanandra, polygama, or purpurea. All kolomikta and polygama accessions were diploid. All arguta, callosa, melanandra, and purpurea accessions were tetraploid. Actinidia deliciosa was hexaploid. One chinensis accession was tetraploid. Two accessions (NGPR 0021.14 and 0021.3), acquired as chinensis, were hexaploid and may, in fact, be A. deliciosa based on their morphology. `Issai' (arguta × polygama) was hexaploid and `Ken's Red' and `Red Princess' (both melanandra × arguta) were tetraploid.

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.

scholarly journals Determination of the relatedness, ease of hybridization and gene exchange among members of the genus Capsicum in Nigeria

2020 ◽  
Vol 12 (3) ◽  
pp. 658-672
Author(s):  
Paul B. AHMODU ◽  
Joseph A. MORAKINYO ◽  
Catherine T. AHMODU
Keyword(s):  
Related Species ◽  
Maternal Inheritance ◽  
Interspecific Crosses ◽  
Gene Exchange ◽  
Closely Related Species ◽  
Partial Dominance ◽  
Leaf Density ◽  
Genus Capsicum ◽  
Flower Position

The fruit of Capsicum plants have a variety of names depending on place and type. This research was focused at studying the exchange of genes amongst members of the genus Capsicum in Nigeria. The process of interspecific and intervarietal hybridization of two (2) species of the genus Capsicum; C. annuum and C. frutasense were carried out and the results show that most of the studied attributes like arrangement of leaves, shape of leaves, leaf density were undetermined while majority with distinct changes follow maternal inheritance. There were less successes among the interspecific crosses and high successes between varietal crosses ranging from 19.5% to 2.4% for the inter-varietal cross and 9.3% to 2.4% for interspecific crosses. This indicates that there are more hybridization barriers among interspecific hybridization than inter-varietal hybridization. The closely related species and varieties had higher percentage success of hybridization and vice versa. Characters such as Hypocotyl colour had partial dominance. Erect flower position is dominant in W and hybrid T*W while pendant is recessive. Red fruit colour at maturity, green fruit stalk colour was dominant while yellow was recessive. A good knowledge of how related species of the genus Capsicum are, the easier it will enable researchers to hybridize and improve the genus.

HYBRID CHLOROSIS IN INTERSPECIFIC CROSSES OF OENOTHERA: POLYGENIC INHERITANCE OF THE NUCLEAR COMPONENT

1974 ◽  
Vol 16 (1) ◽  
pp. 193-201 ◽  
Author(s):  
J. P. van der Meer
Keyword(s):  
Interspecific Hybrids ◽  
The Other ◽  
Interspecific Crosses ◽  
Polygenic Inheritance ◽  
Oenothera Hookeri ◽  
Nuclear Component ◽  
Parallel Series

Interspecific hybrids between Oenothera hookeri or O. elata and O. argillicola are severely chlorotic and die as seedlings because the chloroplasts of either species are unable to function in the presence of the chromosome complex inherited from the other (Stubbe, 1959; Stinson, 1960). In the present investigation the chromosome complex of O. argillicola was genetically partitioned into a number of small sets of chromosomes by means of backcrosses, and the chlorosis-inducing potential of these sets on chloroplasts of O. hookeri and O. elata was determined. The chlorosis-inducing potential of sets of O. hookeri and O. elata chromosomes on the chloroplasts of O. argillicola was determined in a parallel series of crosses.In both series the results indicated that the nuclear component of hybrid chlororis was polygenic. No individual foreign chromosome produced an observable degree of chlorosis while various combinations produced various degrees of chlorosis. In general, the level of the chlorosis paralleled the number of foreign chromosomes in the hybrid, the F-1 hybrid in each case being the most severely affected.

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