Molecular identification and the features of genetic diversity in interspecific hybrids of Amur sturgeon ( Acipenser schrenckii × A. baerii, A. baerii × A. schrenckii, A. schrenckii × A. ruthenus , and A. ruthenus × A. schrenckii ) based on variability of multilocus RAPD markers

The method of polymerase chain reaction with random primers (RAPD PCR) was used to identify the progeny of the crosses between three sturgeon species, Amur sturgeon (Acipenser schrenckii Brandt, 1869), Siberian sturgeon (A. baerii Brandt, 1869), and sterlet (A. ruthenus Linnaeus, 1758). Using ten primers, genetic variation in 70 yearlings, produced in seven individual crosses: Acipenser schrenckii × A. schrenckii, A. baerii × A. baerii, A. ruthenus × A. ruthenus, A. schrenckii × A. baerii, A. baerii × A. schrenckii, A. schrenckii × A. ruthenus, and A. ruthenus × A. schrenckii was described and evaluated. It was demonstrated that the samples composed of hybrids from individual crosses were more variable than the samples of parental species. On the other hand, pooled samples of hybrids from two cross directions were genetically less variable than the pooled samples of their parents. The three main features of the hybrid RAPD profiles identified included: (1) preservation of marker DNA fragments of both parents in one genome; (2) presence of specific DNA fragments, absent from both parents; and (3) dependence of the frequency of some DNA fragments from the cross direction. Multidimensional scaling clearly distinguishes in the space of three coordinates the individuals of original species and the hybrid progeny with differentiation in the groups of direct and backcross hybrids. Analysis of relationships (UPGMA and NJ) pointed to substantial differentiation between the species, as well as between the species and hybrid progeny. Close genetic relationships between direct and backcross hybrids were demonstrated. Multilocus RAPD markers in association with statistical methods are considered to be the useful tool for discrimination of interspecific hybrids of sturgeon. Possible reasons for the differences in the hybrid RAPD profiles are discussed. Original Russian Text ? K.V. Rozhkovan, G.N. Chelomina, E.I. Rachek, 2008, published in Genetika, 2008, Vol. 44, No. 11, pp. 1453–1460.     

Plant regeneration from interspecific hybrid and backcross progeny of Helianthus eggertii × Helianthus annuus

An efficient protocol for plant regeneration from leaves of the interspecific hybrid Helianthus eggertii Small. × Helianthus annuus L. was developed. The regeneration capacity of the first backcross progeny is reported. Leaves from the F1 interspecific hybrid were cultured on Murashige and Skoog basal media (MS) supplemented with -naphthalenacetic acid (NAA), N ⁶-benzyladenine (BA), AgNO₃, KNO₃, casein hydrolysate and adenine sulfate. Embryo-like structures and/or shoots regeneration were observed on most of the tested media. The best results were obtained on media with a higher concentration of cytokinin (8.8 M BA) and lower concentration of auxin (1.08 M NAA). The addition of casein hydrolysate in the media increased the regeneration efficiency. Plant regeneration was achieved via somatic embryogenesis and direct organogenesis. The regeneration potential of leaf, stem and root explants of eighteen first backcross lines was studied. Most of the tested lines were highly regenerable and some of them had DNA content closely related to that of Helianthus annuus L.     

Adventitious bud regeneration and Agrobacterium tumefaciens-mediated genetic transformation of Eucalyptus urophylla × E. tereticornis interspecific hybrid

In Vitro Cellular & Developmental Biology - Plant - A high-efficiency regeneration and genetic transformation system is indispensable for generating desirable traits in important trees such as...     

Somatic embryogenesis and plant regeneration in diploid Allium fistulosum × A. cepa F1 hybrid onions

Procedures were developed for disinfestation of non-dormant basal plate tissue excised from field grown basal plate tissue of diploid Allium fistulosum × A. cepa F₁ hybrid onions. Contamination levels varied with the season and vegetative development of plant material. Callus initiated from basal plate tissue and immature inflorescences of the F₁ hybrids was maintained on a BDS-based medium containing 0.75 mg/l picloram and 2.0 mg/l BA. When this medium was supplemented with vitamins and glycine, and with proline at 2.5 gm/1, somatic embryos began to form. Their development continued on a BDS-based shoot promotion medium containing 0.03 mg/l picloram and 0.32 mg/l 2iP supplemented with vitamins, glycine and proline. Genotypes differed significantly in the numbers of structures regenerated. Plantlets from somatic embryos were rooted into BDS or half-strength BDS medium without growth substances and were successfully transferred to sterilized potting mix in plastic commercial corsage boxes.Abbreviations BA benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - picloram 4-amino-3,5,6-trichloropicolinic acid - 2iP N6-(2-isopentenyl)adenine - NAA 1-naphthylacetic acid - BDS Gamborg's B5 medium modified by Dunstan and Short (1977a)     

Plant regeneration via somatic embryogenesis from suspension cell cultures of Lilium×formolongi hort. Using a bioreactor system

Summary In vitro seedlings of Lilium × formolongi Hort. evs. Norikula, RaiZen No. 1, RaiZen No. 3, RaiZen Early, and Bailansa were used to induce callus by variously modified Murashige and Skoog (MS) media, using protocols for flask culture and bioreactor culture. Green embryogenic callus proliferated from roots near the base of bulblets of five varieties on media containing 0.53–5.3 μM α-naphthaleneacetic acid (NAA), and 28 cell lines were obtained by subcultures on the same medium. For flask culture, the fresh weight (FW) of embryogenic cell clumps doubled every 4 wk on MS basal salts supplemented with 0.53°M NAA and 30 g l⁻¹ sucrose. The maximum frequency of somatic embryos that developed into plantlets was 76.67±17% when plated onto solid MS basal medium without plant growth regulators (PGRs). Among the treatments using four types of bioreactors, the best cell growth and regeneration rate (74±0.14%) of somatic embryos was in a modified 2–1 bioreactor. Cells incubated in the other three bioreactors furned brown and died. Histological study revealed that regeneration was by somatic embryogenesis. The regenerants showed normal growth and flowering after 8–9 mo, in the field. A cell line of cv. Norikula has been subcultured in MS basal salts containing 0.53 μM NAA every 2 mo. for 6 yr. The cell aggregates became more synchronous and many typical embryogenic cells with dense cytoplasm were observed under a light microscope. The long-term embryogenic cells plated on MS basal medium still gave rise to numerous somatic embryos and converted into plantlets.     

Plant regeneration via somatic embryogenesis from solid and suspension cultures of Vitis vinifera L. cv. ‘Manicure Finger’

Vitis vinifera L. cv. ‘Manicure Finger’ is one of the major table grape varieties in China. To provide a strong foundation for genetic transformation with potential for crop improvement, we undertook plant regeneration via somatic embryogenesis. Anthers and gynoecia were harvested from immature flowers and used as explants to induce embryogenic calli. Explants cultured in MS1 medium (based on Murashige and Skoog basal salts), supplemented with 4.5-μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.4-μM 6-benzylaminopurine (6-BA) showed the highest rates of embryogenic callus induction (3.7%?±?1.3% for anthers and 4.8%?±?2.5% for gynoecia). After several months, somatic embryos were produced from embryogenic calli cultured in plant growth regulator-free MS2 medium (with reduced sucrose). Somatic embryos (SE) at the cotyledonary stage were isolated and cultured on three different media (MS2, MS3, or B) for conversion into plantlets, the efficiency of which ranged from 63.9%?±?4.8% to 83.9%?±?8.4%. After 1 mo of in vitro culture, 80% of plants with at least six leaves were successfully transplanted into soil. SE was repeatedly induced from previously induced somatic embryos for up to 1.5 yr. Using embryogenic calli as starting material, suspension cultures containing embryogenic cell aggregates were also established in liquid MS medium supplemented with 4.5-μM 2,4-D. The embryogenic cell aggregates continued to proliferate without differentiating for successive subculture cycles. After transfer to 2,4-D-free liquid medium for 4 wk, an average of 63.7%?±?9.0% mature SEs were produced per 20 mL of liquid medium. More than 40% of somatic embryos at cotyledonary stage, derived from the suspension cultures, successfully germinated into plants using solid medium.     

Comparative cytogenetic analysis of the “Sylvaemus” group of Apodemus (Rodentia, Muridae): A. sylvaticus from Sicily and A. flavicollis from the central Apennines

Chromosome mapping of three common markers, ie major and 5S rRNA genes (rDNA) and telomeric repeats, and conventional chromosome bandings were applied to two sibling species, Apodemus sylvaticus Linnaeus, 1758 and A. flavicollis Melchior, 1834, to further investigate intra- and interspecific karyological differentiation in the genus Apodemus. A slight variation of the rDNA-patterns was detected between the two Apodemus species. In both of them, the major NORs were located on autosome pairs 8, 11, 12 and 22, while the two other rDNA sites detected on chromosomes 7 and 21 were variable in, respectively, A. sylvaticus and A. flavicollis. Several tiny rDNA sites were present on the sex chromosomes in both species, but their incidence was lower in A. flavicollis. Single 5S rDNA chromosomal sites were conserved on chromosome pair 20. No interstitial sites of telomeric repeats were present in either species. In the Sicilian population of A. sylvaticus, the constitutive heterochromatin pattern corresponded to the “sylvaticus-E1” cytotype, while A. flavicollis had a species-specific pattern restricted to centromeres of all chromosomes. The results are discussed in relation to cytogenetic data available for the genus, with emphasis on the Sylvaemus group/subgenus.     

Tomato chromosome 1: high resolution genetic and physical mapping of the short arm in an interspecific Lycopersicon esculentum × L. peruvianum cross

 A detailed map of part of the short arm of chromosome 1 proximal to the Cf-4/Cf-9 gene cluster was generated by using an F₂ population of 314 plants obtained from the cross between the remotely related species Lycopersicon esculentum and L. peruvianum. Six markers that cosegregate in an L. esculentum×L. pennellii F₂ population showed high recombination frequencies in the present interspecific population, spanning an interval of approximately 13 cM. Physical distances between RFLP markers were estimated by pulsed field gel electrophoresis of high-molecular-weight DNA and by identifying YACs that recognized more than one RFLP marker. In this region 1 cM corresponded to 55–110 kb. In comparsion with the value of 730 kb per cM averaged over the entire genome, this reflects the remarkably high recombination frequencies in this region in the hybrid L. esculentum×L. peruvianum progeny population. The present data underline the fact that recombination is not a process that occurs randomly over the entire genome, but can vary dramatically in intensity between chromosomal regions and among populations. Received: 20 May 1996 / Accepted: 10 September 1996     

Effects of β-lactam antibiotics, auxins, and cytokinins on shoot regeneration from callus cultures of two hybrid aspens, Populustremuloides?×?P. tremula and P. xcanescens?×?P. gradidentata

The effects of β-lactam antibiotics (penicillin, carbenicillin and cefotaxime), cytokinins, and auxins including phenylacetic acid, a β-lactam breakdown product, were evaluated during in vitro shoot morphogenesis in two hybrid aspens; P. tremuloides × P. tremula (XTTa) and P. x canescens × P. grandidentata (XCaG). Although different callus and shoot induction media were used for both hybrids, the β-lactams often engendered similar responses. At concentrations of 1,000 mg l⁻¹, carbenicillin adversely impacted shoot elongation and, to a lesser degree, shoot regeneration. Cefotaxime enhanced caulogenesis for all of the concentrations evaluated (125–500 mg l⁻¹) especially when the cytokinin thidiazuron was used for shoot induction. The shoots formed faster and in greater numbers; and the improvements were significant (α = 0.05) for both hybrids. However, hyperhydricity was more problematic when cefotaxime was included in the media. The incidence of shoot hyperhydricity for the XCaG hybrid was more than twice as great for the highest cefotaxime concentration evaluated (500 mg l⁻¹) than for the control (>90% vs. ~40%). Penicillin had an opposite effect. Hyperhydricity frequencies for the XCaG hybrid were lower when the media were supplemented with penicllin and the reductions were statistically significant at concentrations of 500–1,000 mg l⁻¹. The effects of the antibiotics were generally not reproduced by the auxins (0.1–100 μM), including phenylacetic acid, or the other potential β-lactam degradation products evaluated (e.g. phenylmalonic acid, aminopenicillanic acid). The antibiotics may have affected shoot hyperhydicity indirectly via changes in the time course of shoot regeneration.     

A wild Marsh Warbler?×?Sedge Warbler hybrid (Acrocephalus palustris?×?A. schoenobaenus) in Norway documented with molecular markers

We present photographic and molecular evidence of a wild Marsh Warbler × Sedge Warbler (Acrocephalus palustris × A. schoenobaenus) hybrid that occurred over three breeding seasons (2007–2009) near Trondheim, Central Norway. The bird had the appearance of a Marsh Warbler but with some typical Sedge Warbler plumage traits. DNA analyses of a few plucked body feathers, using the COI barcode region (mtDNA) and conserved microsatellite loci, confirmed that the bird was a hybrid, with a Marsh Warbler mother and a Sedge Warbler father.     

Apoptotic cell death induces temperature-sensitive lethality in hybrid seedlings and calli derived from the cross of Nicotiana suaveolens×N. tabacum

Hybrid lethality expressed in the interspecific hybrid of Nicotiana suaveolens Lehm. ×N. tabacum L. cv. Hicks-2 is one of the mechanisms for reproductive isolation and it is temperature-sensitive. Apoptotic changes were detected in the cells of hybrid seedlings and calli expressing lethality at 28 °C but not under high-temperature conditions (36 °C), when the lethality is suppressed. Condensation of chromatin, fragmentation of nuclei and cytoplasmic reduction are the cytological changes associated with apoptosis leading to hybrid lethality. Fragmentation of nuclei was correlated with the lethal symptoms in both hybrid seedlings and calli, as confirmed by fluorimetry of the nuclear DNA using laser scanning cytometry. Agarose gel analysis of DNA extracted from hybrid seedlings and calli showing lethal symptoms revealed a specific ladder pattern suggesting nucleosomal fragmentation which is one of the biochemical changes of apoptosis. In-situ detection using terminal deoxyribonucleotidyl transferase-mediated dUTP-fluorescein nick end labeling (TUNEL) showed that this process occurred in distinct stages on each organ of hybrid seedlings and centripetally in hybrid calli. From these results, we confirmed that cell death inducing hybrid lethality was indeed apoptosis. Received: 23 December 1999 / Accepted: 5 April 2000     

Phylogeny and expression profiling of CAD and CAD-like genes in hybrid Populus (P. deltoides × P. nigra): evidence from herbivore damage for subfunctionalization and functional divergence

Background  

Cinnamyl Alcohol Dehydrogenase (CAD) proteins function in lignin biosynthesis and play a critical role in wood development and plant defense against stresses. Previous phylogenetic studies did not include genes from seedless plants and did not reflect the deep evolutionary history of this gene family. We reanalyzed the phylogeny of CAD and CAD-like genes using a representative dataset including lycophyte and bryophyte sequences. Many CAD/CAD-like genes do not seem to be associated with wood development under normal growth conditions. To gain insight into the functional evolution of CAD/CAD-like genes, we analyzed their expression in Populus plant tissues in response to feeding damage by gypsy moth larvae (Lymantria dispar L.). Expression of CAD/CAD-like genes in Populus tissues (xylem, leaves, and barks) was analyzed in herbivore-treated and non-treated plants by real time quantitative RT-PCR.     

Neotropical Monogenoidea. 54. Proposal of Aetheolabes n. g. (Dactylogyrinea: Diplectanidae), with the description of A. goeldiensis n. sp. from the gills of ‘pescada’ Plagioscion sp. (Teleostei: Sciaenidae) in Brazil

Aetheolabes goeldiensis n. g., n. sp. (Diplectanidae) is described from the gills of ‘pescada’ Plagioscion sp. (Sciaenidae) collected from the Baía de Marajó, about 30 km north of Belém, Pará, Brazil. The monotypic Aetheolabes n. g. is characterised, in part, by its type-species having the haptor and haptoral sclerites modified as a clasp for attachment to the gill tissue of its host, the copulatory complex situated far posterior to the intestinal bifurcation near the mid-length of the trunk, the vaginal pore apparently within the genital atrium, the tegument lacking scales, anchors atypical for diplectanids, and by lacking peduncular spines and squamodiscs. A. goeldiensis n. sp. closely resembles Diplectanum umbrinum Tripathi, 1957 from India and China by the haptoral sclerites forming a clasp, but differs from it primarily by the orientation of the reproductive organs and absence of squamodiscs.     

A ThCAP gene from Tamarix hispida confers cold tolerance in transgenic Populus (P. davidiana?×?P. bolleana)

The ThCAP gene, which encodes a cold acclimation protein, was isolated from a Tamarix hispida NaCl-stress root cDNA library; its expression patterns were then assayed by qRT-PCR in different T. hispida tissues treated with low temperature (4°C), salt (400 mM NaCl), drought (20% PEG6000) and exogenous abscisic acid (100 μM). Induction of ThCAP gene was not only responsive to different stress conditions but was also organ specific. When transgenic Populus (P. davidiana × P. bolleana) plants were generated, expressing ThCAP under regulation of the cauliflower mosaic virus CaMV 35S promoter, they had a greater resistance to low temperature than non-transgenic seedlings, suggesting that ThCAP might play an important role in cold tolerance.     

Genetic mapping and QTL analysis for yield and agronomic traits with an F2:3 population derived from a waxy corn × sweet corn cross

We constructed a framework map using SSR markers in the F₂ population derived from a cross between a waxy corn inbred line and a sweet corn inbred line. We constructed a genetic linkage map of the F_2:3 population employing 295 SSR markers on 158 F₂ individuals produced from the cross. The map comprised a total genomic length of 2,626.5 cM in 10 linkage groups and an average distance between markers of 8.9 cM. The number of loci per linkage group ranged from 27 (chr. 5) to 34 (chr. 7). The genetic distance per linkage group ranged from 213.6 cM (chr. 10) to 360.6 cM (chr. 2). Χ ² tests revealed that 254 markers (86.1 %) distributed over all 10 chromosomes exhibited a Mendelian segregation ratio of 1:2:1. A total of 14 quantitative trait loci (QTLs) for days to silking (DTS), plant height (PH), ear height (EH), ear height ratio (ER), ear length (L-ear), and setted ear length (L-sear) were found in the 158 F₂ progeny. They were mapped to chromosomes 1, 2, 3, 7, 8, and 10. Among them, one QTL was associated with DTS, three with PH, six with EH, one with ER, two with L-ear, and one QTL was related to L-sear. In our study, we found that four QTLs: qDTS1, qEH1a, qEH1b, and qPH1, were clustered between umc2390 and umc1603 on chromosome 1. These new QTLs identified by the present study could serve as useful molecular markers in selecting for yield and agronomic traits in maize. The results of this study may improve the identification and characterization of genes responsible for yield and agronomic traits in waxy corn and sweet corn.     

Analysis of storage proteins (prolamines, puroindolines and Waxy) in common wheat lines Triticum aestivum L. × (Triticum timopheevii Zhuk. × Triticum tauschii) with complex resistance to fungal infections

Storage proteins (prolamines, puroindolines, and Waxy) were studied in common wheat introgression lines obtained with the use of the Saratovskaya 29 (S29) cultivar line and synthetic hexaploid wheat (Triticum timopheevii Zhuk. × T. tauschii) (Sintetik, Sin.) displaying complex resistance to fungal infections. Comparative analysis of storage proteins in the introgression lines of common wheat Triticum aestivum L. and in the parental forms revealed the only line (BC5) having a substitution at the Gli-B2 locus from Sintetik. Hybrid lines subjected to nine backcrosses with the recurrent parental form S29 and selections for resistance to pathogens can be considered as nearly isogenic for the selected trait and retaining the allelic composition of (1) prolamines responsible for the bread-making qualitiy, (2) puroindolines associated with grain texture, and (3) Waxy proteins responsible for nutritive qualities. These lines are valuable as donors of immunity in breeding programs without the loss of the quality of flour and grain as compared to the S29 line and are also important in searching for genes determining resistance to leaf and stem rust and to powdery mildew. The amphiploid has a number of characters (silent Glu-A1 locus and Ha genotype) that can negatively affect the quality of flour and grain and thus should be taken into account when choosing this donor.     

Tomato chromosome 1: high resolution genetic and physical mapping of the short arm in an interspecific Lycopersicon esculentum×L. peruvianum cross

A detailed map of part of the short arm of chromosome 1 proximal to the Cf-4/Cf-9 gene cluster was generated by using an F₂ population of 314 plants obtained from the cross between the remotely related species Lycopersicon esculentum and L. peruvianum. Six markers that cosegregate in an L. esculentum×L. pennellii F₂ population showed high recombination frequencies in the present interspecific population, spanning an interval of approximately 13?cM. Physical distances between RFLP markers were estimated by pulsed field gel electrophoresis of high-molecular-weight DNA and by identifying YACs that recognized more than one RFLP marker. In this region 1?cM corresponded to 55–110?kb. In comparsion with the value of 730?kb per cM averaged over the entire genome, this reflects the remarkably high recombination frequencies in this region in the hybrid L. esculentum×L. peruvianum progeny population. The present data underline the fact that recombination is not a process that occurs randomly over the entire genome, but can vary dramatically in intensity between chromosomal regions and among populations.     

Detection of QTLs associated with shoot wilting and root ammonium uptake under chilling temperatures in an interspecific backcross population from Lycopersicon esculentum ×L. hirsutum

The genetic basis for shoot wilting and root ammonium uptake under chilling temperatures was examined in an interspecific backcross (BC₁) population derived from Lycopersicon esculentum Mill. cv T5 and wild Lycopersicon hirsutum f. typicum accession LA1778. The chilling sensitivity of shoot wilting and ammonium uptake was evaluated in four replicated cuttings from each of 196 BC₁ plants. Wilting was evaluated at two different times: 2 hours (wilting 2 h) and 6 hours (wilting 6 h recovery) after root exposure to 4°C. The BC₁ plants were genotyped with 89 polymorphic RFLP markers, and composite interval mapping was used to detect quantitative trait loci (QTLs). Three QTLs, one each on chromosomes 5, 6 and 9, were detected for wilting 2 h. The presence of a L. hirsutum (H) allele at the QTL on chromosomes 5 and 9 decreased wilting, while the H allele at the QTL on chromosome 6 increased wilting. To analyze plant recovery from wilting at 6 h, subsets of the BC₁ population were selected, based on phenotype and genotype, because not all plants wilted at 2 h. The phenotype subset (wilting 6 h-PS) included plants that wilted to a greater degree at 2 h, and the genotype subsets included plants carrying specific allelic compositions at the QTL for wilting 2 h on chromosomes 5 (wilting 6 h-GS-ch5), 6 (wilting 6 h-GS-ch6), and 9 (wilting 6 h-GS-ch9). On chromosome 6, a QTL was located that was associated with three subsets (wilting 6 h-PS, wilting 6 h-GS-ch5 and wilting 6 h-GS-ch9), while on chromosome 7 a QTL was detected with two subsets (wilting 6 h-PS and wilting 6 h-GS-ch5). Three additional QTLs were detected within a single subset: chromosome 1 (wilting 6 h-GS-ch6), chromosome 11 (wilting 6 h-GS-ch5) and chromosome 12 (wilting 6 h-GS-ch9). The presence of the H allele at the QTL on chromosomes 7 and 12 had a positive effect, enhancing recovery from wilting, while the H allele at the other QTL had a negative effect. Three traits were used to evaluate the chilling sensitivity of root ammonium uptake: ammonium uptake before a chilling episode, ammonium uptake after the chilling episode, and the relative inhibition of uptake (difference in uptake rates before and after chilling divided by the rate before chilling). One QTL was detected on chromosome 3 for the rate before chilling and one on chromosome 6 for the relative inhibition of ammonium uptake. Our results demonstrate that shoot wilting and ammonium uptake under chilling are controlled by multiple QTLs. Received: 10 August 1999 / Accepted: 25 March 2000     

Callus induction and plant regeneration from mature zygotic embryos of a tetraploid Alstroemeria (A. pelegrina × A. psittacina)

Summary A simple procedure was developed to induce callus growth and whole plant regeneration for a tetraploid cultivar of Alstroemeria. The callus, induced from mature zygotic embryos cultured on a medium supplemented with 20 M kinetin with 10 or 20 M NAA, could be maintained for one year without any loss of regeneration potential. Maximum frequency of regeneration (40%) was obtained with calli maintained on the medium containing 20 M kinetin and 20 M NAA. Whole plant regeneration occurred via somatic embryogenesis in the absence of growth regulators and the plantlets grew to maturity and flowered in the greenhouse conditions.Abbreviations BAP N⁶-benzylaminopurine - MS Murashige and Skoog (1962) medium - MSO Basal medium devoid of any plant growth regulator - NAA -Naphthaleneacetic acid - TDZ N-phenyl-N 1,2,3,-thiadiazol-5-ylurea (thidiazuron) - IAA Indole-3-acetic acid - 2,4-D 2,4-Dichlorophenoxyacetic acid