Progeny Plants Research Articles

Dynamics of Glyphosate Resistance in Lolium perenne: Pollen-Mediated Gene Flow under Field Conditions in Argentina

The genus Lolium has shown a high tendency to evolve resistance to herbicides. Considering the high level of allogamy of L. perenne and the importance of the wind as an agent for pollen dispersion, the aim of this work was to assess and quantify the effective glyphosate-resistant gene flow by pollen in L. perenne under field conditions. Pollen-mediated gene flow from glyphosate-resistant to -susceptible plants was studied using a donor–receptor design. The results indicate that the effective gene flow reached trap plants distanced ≤35 m downwind from the source of pollen. The progeny of receptor plants growing 0 m from the pollen donors showed 13% of individuals with low glyphosate sensitivity. This represents a seven-fold increase in the frequency of glyphosate-resistant individuals found in the progeny of plants isolated during the flowering period (negative control). Similarly, the progenies of plants grown at 15 and 25 m from the source of glyphosate resistance showed an increase in the frequency of resistant plants by about four- and two-fold, respectively. When the receptor plants were located at >35 m, no glyphosate-resistant plants were detected in their progenies. Management should aim for prevention or delay of flowering of glyphosate-resistant plants.

Limonium homoploid and heteroploid intra‐ and interspecific crosses unveil seed anomalies and neopolyploidy related to sexual and/or apomictic reproduction

AbstractApomixis is a form of asexual reproduction that consists in cloning through seeds. In Limonium (Plumbaginaceae) species present a pollen–stigma dimorphism linked to a sporophytic self‐incompatibility system associated with sexual and/or apomictic reproductive modes. Previous work in other genera suggests that the emergence of apomixis is associated with hybridization and/or polyploidy. In this study, our goal was to test the ability of diploid and tetraploid species to hybridize and to evaluate the variate outcomes from these crosses. To achieve this, sexual diploid (L. nydeggeri, L. ovalifolium) and facultative apomict tetraploid (L. binervosum, L. dodartii) plants from cultivated material, previously cytogenetically and reproductively characterized, were used for experimental intra‐ and interspecific crosses. Genome sizes, ploidy levels and morphology were examined in the resulting progenies. Results showed a high production of viable seeds in particular in plants from tetraploid × diploid (heteroploid) crosses. In these crosses, some seedlings exhibited pleiocotyly (tricotyl, tetracotyl), while others showed polyembryony. In both homoploid (diploid × diploid) and heteroploid (tetraploid × diploid) crosses, most of the offspring plants were morphologically and in their ploidy similar to the female receiver, although some morphological abnormalities were found. Molecular progeny tests using the nrDNA ITS1‐ITS2 sequence demonstrated an astounding range of diploid offspring plants originated from diploid × diploid crosses that were either genetically similar or distinct from parental plants. Although in intraspecific crosses most of the resulting progeny was diploid, one triploid plant was formed. Moreover, in homoploid interspecific crosses, neopolyploids (two tetraploid plants) were produced. Progeny plants from heteroploid crosses always showed nrDNA ITS1‐ITS2 sequences identical to the parental plant used as female receiver. In conclusion, diploid homoploid crosses presented genetically diverse offspring arising from sexual reproduction. By contrast, heteroploid crosses generated clonal, maternal (apomictic) offspring.

Drought stress has transgenerational effects on seeds and seedlings in winter oilseed rape (Brassica napus L.)

BackgroundDrought stress has a negative effect on both seed yield and seed quality in Brassica napus (oilseed rape, canola). Here we show that while drought impairs the maternal plant performance, it also increases the vigour of progeny of stressed maternal plants. We investigated the transgenerational influence of abiotic stress by detailed analysis of yield, seed quality, and seedling performance on a growth-related and metabolic level. Seeds of eight diverse winter oilseed rape genotypes were generated under well-watered and drought stress conditions under controlled-environment conditions in large plant containers.ResultsWe found a decrease in seed quality in seeds derived from mother plants that were exposed to drought stress. At the same time, the seeds that developed under stress conditions showed higher seedling vigour compared to non-stressed controls.This effect on seed quality and seedling vigour was found to be independent of maternal plant yield performance.ConclusionsDrought stress has a positive transgenerational effect on seedling vigour. Three potential causes for stress-induced improvement of seedling vigour are discussed: (1) Heterotic effects caused by a tendency towards a higher outcrossing rate in response to stress; (2) an altered reservoir of seed storage metabolites to which the seedling resorts during early growth, and (3) inter-generational stress memory, formed by stress-induced changes in the epigenome of the seedling.

Simple DNA marker-assisted selection of endophyte (Epichloë uncinata )-infected festulolium

In this study, to breed endophyte (Epichloe uncinata)‐infected festololium (x Festulolium Aschers.et Graebn.), we backcrossed endophyte‐infected Italian ryegrass (Lolium multiflorum Lam.) to festulolium. To prevent self‐pollinated plants being mixed with the progeny, we used polymerase chain reaction (PCR)‐based DNA marker sets distinguishing between Lolium and Festuca species. In the first backcrossing (F₁ development), 20 of the 21 progeny plants showed Festuca‐specific band patterns and were endophyte‐infected. We developed six maternal lines (BC₁ development) by backcrossing six selected F₁ plants. More than 97% of plants from five maternal lines had novel Festuca‐specific band patterns which their maternal parents lacked. However, only 54% plants of the maternal line F₁–₁₈ exhibited novel Festuca‐specific band patterns. F₁–₁₈ showed Festuca‐specific band patterns with almost all tested DNA marker sets, and its f ratio (the ratio of Festuca‐specific region to the whole genome) was 31.1%, indicating that F₁–₁₈ had an almost complete set of the Festuca genome. Because paternal backcrossing festulolium parents were amphidiploids, an f ratio of approximately 25% corresponds to a complete set of the Festuca genome. We found that it was difficult to evaluate BC₂ hybridity using the same DNA marker sets because very few DNA markers were distinctive. In total, we bred and selected at least 146 true BC₁ hybrids and endophyte‐infected plants using DNA markers.

Agrobacterium mediated in planta transformation in castor (Ricinus communis L.)

Castor has been a recalcitrant crop for in vitro manipulations. To realize the potential of genetic engineering, it is essential to develop a repeatable transformation protocol. In planta transformation has been identified as a method of choice to obtain transgenic lines in crops that are trajectory to in vitro procedures. In the present investigation, we have developed an optimized protocol for realizing transgenic castor plantsthrough Agrobacterium mediated in planta transformation. We have established procedures to ensure better survival of Agrobacterium treated seedlings (T0) in transgenic green house as well as for screening T1 progeny plants to identify putative transgenic plants. The optimized factors included : growing the Agro-treated (pricked) seedlings for two days in soilrite and then transferring to soil, treating the two day old seedlings of T1 progeny plants in hygromycin solution @40mg/l for two hours and then transferring the normal looking plants to the soil in transgenic green house. Using the optimized protocol, we have realized 30 transgenic castor plants carrying different gene constructs.

Genetic variability to improve yield and resistance to bacterial leaf blight in rice

One hundred F2 and F3 single plant progenies along with their parents and the infector rows were evaluated for 13 quantitative traits to assess the genetic variability, heritability, associations and estimation of number of genes for bacterial leaf blight resistance and yield related traits. In both F2 and F3, a wide range of variability was present for all the traits, indicating considerable scope for selection. High heritability accompanied with high genetic advance was observed for plant height, panicle length, panicle weight, number of effective tillers per plant and grain yield per plant. Positive and significant correlation were observed between grain yield per plant with days to 50% flowering, plant height, panicle length, panicle weight, number of effective tillers per plant, test weight and flag leaf length in either one of the generation or in combination of both F2 and F3. Path-coefficients analysis showed that plant height, panicle length and test weight had high direct positive effect in both the F2 and F3. The estimated number of gene(s) in the segregating generations for bacterial leaf blight was 2.14 in the F2 and 0.92 in the F3 revealed that two genes were involved in the inheritance of resistance to bacterial leaf blight in F2, while only one gene in F3 due to dominance effect.

Development and studying of Triticum aestivum L. material with introgressions from Aegilops biuncialis Vis.

Aim. The aim of the study was to develop and study T. aestivum material with introgressions from Ae. biuncialis. Methods. Quantitative traits of F4 lines from crossing wheat with Crimean accessions of Ae. biuncialis were studied. SDS and APAG electrophoreses of storage proteins were used to identify alleles at the Glu-1 and Gli-1 loci, including introgressed ones. Results. F4 lines from crosses of wheat with Ae. biuncialis showed a wide range of yield traits. Some lines had a clavate spike and a hairy leaf blade. Using storage proteins as genetic markers the presence of chromosome 1U was identified among the progeny of plants analyzed; some of them had translocation of arm 1UL. Lines with introgressions of chromosome 1M were not revealed. Conclusions. T. aestivum lines with introgressions from Ae. biuncialis were developed without amphidiploid production. Lines with chromosome 1U were selected, including lines with translocations of arm 1UL.
 Keywords: Triticum aestivum L., Aegilops biuncialis Vis., introgression.

Gentian (Gentiana triflora) prevents transmission of apple latent spherical virus (ALSV) vector to progeny seeds.

Gentian plants ( Gentiana triflora ) severely restrict apple latent spherical virus (ALSV) invasion to the gametes (pollens and ovules) and block seed transmission to progeny plants. Early flowering of horticultural plants can be induced by infection of ALSV vector expressing Flowering Locus T (FT) gene. In the present study, flowering of gentian plants was induced by infection with an ALSV vector expressing a gentian FT gene and the patterns of seed transmission of ALSV in gentian were compared with those in apple and Nicotiana benthamiana. Infection of gentian progeny plants with ALSV was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), reverse transcription-loop-mediated isothermal amplification (RT-LAMP), and enzyme-linked immunosorbent assay (ELISA). ALSV was not transmitted to the progeny gentian plants, whereas small proportions of apple and N. benthamiana progeny plants are infected with ALSV. The in situ hybridization analyses indicated that ALSVs are not present in gentian pollen and ovules, but detected in most of gametes in apple and N. benthamiana. Collectively, these results suggest that seed transmission of ALSV is blocked in gentian plants through the unknown barriers present in their gametes. On the other hand, apple and N. benthamiana seem to minimize ALSV seed transmission by inhibiting viral propagation in embryos.

RNA-seq analysis of lignocellulose-related genes in hybrid Eucalyptus with contrasting wood basic density

BackgroundWood basic density (WBD), the biomass of plant cell walls per unit volume, is an important trait for elite tree selection in kraft pulp production. Here, we investigated the correlation between WBD and wood volumes or wood properties using 98 open-pollinated, 2.4 to 2.8 year-old hybrid Eucalyptus (Eucalyptus urophylla x E. grandis). Transcript levels of lignocellulose biosynthesis-related genes were studied.ResultsThe progeny plants had average WBD of 516 kg/m3 with normal distribution and did not show any correlations between WBD and wood volume or components of α-cellulose, hemicellulose and Klason lignin content. Transcriptomic analysis of two groups of five plants each with high (570–609 kg/m3) or low (378–409 kg/m3) WBD was carried out by RNA-Seq analysis with total RNAs extracted from developing xylem tissues at a breast height. Lignocellulose biosynthesis-related genes, such as cellulose synthase, invertase, cinnamate-4-hydroxylase and cinnamoyl-CoA reductase showed higher transcript levels in the high WBD group. Among plant cell wall modifying genes, increased transcript levels of several expansin and xyloglucan endo-transglycosylase/hydrolase genes were also found in high WBD plants. Interestingly, strong transcript levels of several cytoskeleton genes encoding tubulin, actin and myosin were observed in high WBD plants. Furthermore, we also found elevated transcript levels of genes encoding NAC, MYB, basic helix-loop-helix, homeodomain, WRKY and LIM transcription factors in the high WBD plants. All these results indicate that the high WBD in plants has been associated with the increased transcription of many genes related to lignocellulose formation.ConclusionsMost lignocellulose biosynthesis related genes exhibited a tendency to transcribe at relatively higher level in high WBD plants. These results suggest that lignocellulose biosynthesis-related genes may be associated with WBD.

Legacy effects of herbivory enhance performance and resistance of progeny plants

Abstract Herbivory‐induced changes in plant resistance and tolerance traits can mediate the interaction between spatially and temporally separated above‐ and below‐ground herbivores. However, it is unknown how long the impact of transient herbivory events last or if legacy effects can be detected systemically in the plant and across plant generations. Here, we studied the impact of transient above‐ground herbivory by the specialist caterpillar Manduca sexta on the plant traits of wild tobacco Nicotiana attenuata and the consequences for below‐ground root‐knot nematodes Meloidogyne incognita in short‐term, long‐term, and transgenerational experiments. In the short‐ and long‐term experiments, above‐ and below‐ground herbivory had significant, albeit independent, impacts on key plant traits such as plant biomass, nutrient content, and secondary metabolites. In addition, herbivory influenced fitness parameters such as seed yield and quality. In the long‐term and transgenerational experiments, transient above‐ground herbivory had facilitating effects on nematodes, irrespective of any treatments of the parental plants. We found evidence for transgenerational legacy effects of both above‐ and below‐ground herbivory on the resistance of progeny plants against above‐ground herbivores. Additionally, below‐ground herbivory in the parental generation increased the root biomass of progeny plants. Synthesis. Our results suggest that herbivory may have a long‐term impact on plant fitness by improving the performance of progeny plants challenged by above‐ and below‐ground herbivory.

Transgenerational effect of maternal growth environment on flowering date in rice (Oryza sativa L.)

Flowering date reflects the adjustment of a plant’s growth period to a given environment. This is true of rice, which is a major food source around the world. We tested whether rice plants can recognize and record natural variation in their growth environments and thus control flowering in their progeny. We grew seedlings of two japonica cultivars from the same seed stock at two locations, in cool and warm climates, in Japan until they produced seeds. We then tested their progeny at the same locations. The progeny of mother plants of both cultivars grown in a cool climate flowered significantly earlier (by 1 to 6 days) than the progeny of mother plants grown in a warm climate. This transgenerational effect was partially explained by water temperatures during the vegetative growth stage. This is the first study to show the effect of transgenerational effect of natural environments on flowering date in rice.

Introgression and inheritance of charcoal rot (Macrophomina phaseolina) resistance from silver sunflower (Helianthus argophyllus Torr. & A. Gray) into cultivated sunflower (Helianthus annuus L.)

Charcoal rot is a devastating disease of sunflower causing significant yield losses. There is a lack of high-level resistance in cultivated germplasm for this disease. The purpose of this study was to incorporate resistance against charcoal rot into cultivated sunflower lines. The study indicated that sunflower elite cultivated germplasm was susceptible which showed complete stunting of growth and wilting when compared with wild accessions of Helianthus argophyllus. H. argophyllus was identified as immune for charcoal rot and has the potential to diversify the initial source of disease resistance in sunflower elite germplasm. The segregating ratios in the F2 generation showed the presence of two major genes having an epistatic interaction to control immunity while a single gene was found to control disease resistance or partial resistance. Stem color showed the highest correlation with disease scoring which may be used to differentiate resistant and susceptible plant progenies. The F3 progenies selected on the basis of this trait resulted in the selection of all types of resistance in the F4 generation with an immune class having a minimal reduction in or deterioration of morphological traits. Stem color also correlated with stem toughness (r = 0.46**), and as a result, plant genotypes with tough stems were selected. The selected progenies will be registered as a source of charcoal rot resistance.

A microorganisms\u2019 journey between plant generations

BackgroundPlants are colonized by a great diversity of microorganisms which form a microbiota and perform additional functions for their host. This microbiota can thus be considered a toolbox enabling plants to buffer local environmental changes, with a positive influence on plant fitness. In this context, the transmission of the microbiota to the progeny represent a way to ensure the presence of beneficial symbionts within the habitat. Examples of such transmission have been mainly described for seed transmission and concern a few pathogenic microorganisms. We investigated the transmission of symbiotic partners to plant progeny within clonal plant network.MethodsWe used the clonal plant Glechoma hederacea as plant model and forced newly emitted clonal progeny to root in separated pots while controlling the presence of microorganisms. We used an amplicon sequencing approach of 16S and 18S rRNA targeting bacteria/archaea and fungi respectively to describe the root microbiota of mother and clonal-plant offspring.ResultsWe demonstrated the vertical transmission of a significant proportion of the mother plants’ symbiotic bacteria and fungi to the daughters. Interestingly, archaea were not transmitted to the daughter plants. Transmitted communities had lower richness, suggesting a filtration during transmission. We found that the transmitted pool of microorganisms was similar among daughters, constituting the heritability of a specific cohort of microorganisms, opening a new understanding of the plant holobiont. We also found significant effects of distance to the mother plant and of growth time on the richness of the microbiota transmitted.ConclusionsIn this clonal plant, microorganisms are transmitted between individuals through connections, thereby ensuring the availability of microbe partners for the newborn plants as well as the dispersion between hosts for the microorganisms. This previously undescribed ecological process allows the dispersal of microorganisms in space and across plant generations. As the vast majority of plants are clonal, this process might be therefore a strong driver of ecosystem functioning and assembly of plant and microorganism communities in a wide range of ecosystems.

Efficient genome editing of wild strawberry genes, vector development and validation.

SummaryThe clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 system is an effective genome editing tool for plant and animal genomes. However, there are still few reports on the successful application of CRISPR–Cas9 to horticultural plants, especially with regard to germ‐line transmission of targeted mutations. Here, we report high‐efficiency genome editing in the wild strawberry Fragaria vesca and its successful application to mutate the auxin biosynthesis gene TAA1 and auxin response factor 8 (ARF8). In our CRISPR system, the Arabidopsis U6 promoter AtU6‐26 and the wild strawberry U6 promoter FveU6‐2 were each used to drive the expression of sgRNA, and both promoters were shown to lead to high‐efficiency genome editing in strawberry. To test germ‐line transmission of the edited mutations and new mutations induced in the next generation, the progeny of the primary (T0) transgenic plants carrying the CRISPR construct was analysed. New mutations were detected in the progeny plants at a high efficiency, including large deletions between the two PAM sites. Further, T1 plants harbouring arf8 homozygous knockout mutations grew considerably faster than wild‐type plants. The results indicate that our CRISPR vectors can be used to edit the wild strawberry genome at a high efficiency and that both sgRNA design and appropriate U6 promoters contribute to the success of genomic editing. Our results open up exciting opportunities for engineering strawberry and related horticultural crops to improve traits of economic importance.

Acquisition of triploid germplasms by controlled hybridisation between diploid and tetraploid in Chinese jujube

ABSTRACT‘Chenguang’ is the first released tetraploid cultivar (2n = 4x = 48) of Chinese jujube (Ziziphus jujuba Mill.) induced by colchicine. The purpose of this study was to create triploid germplasms by using ‘Chenguang’ as a parent. The controlled crosses between autotetraploid ‘Chenguang’ and diploid ‘Dongzao’ were carried out from 2013 to 2015 by maintaining the 2 parents in a nylon net and employing bees as pollinator. A total of 606 fruits were produced, yet only 17 seeds were obtained from ‘Dongzao’ and none from ‘Chenguang’. Direct sowing of the seeds in greenhouse showed a higher seedling rate than embryo culture. Four progeny plants were eventually obtained in the greenhouse and all of them were confirmed as authentic hybrids by SSR marker technique. At last, 3 triploids and 1 diploid were identified by flow cytometric analysis. Consequently, tetraploid ‘Chenguang’ with high pollen vitality and pollen number per anther could be used as a reliable 2n pollen provider, and the 2x × 4x cross combination type is more suitable for triploid creation in Chinese jujube. This is the first successful production of triploid hybrids by controlled cross between diploids and tetraploids in jujube.

Dissection of gene loci underlying pasting temperature in cassava

ABSTRACTIn this study, a fine genetic map within the quantitative trait loci (QTL) underlying pasting temperature (PT) of cassava (Manihot esculenta Crantz) was constructed using newly developed simple sequence repeat (SSR) markers. The SSRs were designed on the basis of two scaffolds (S11341 and S4043) of the cassava genome, which covered previously identified QTL regions of the PT trait. A total of 55 and 61 SSR markers derived from S11341 and S4043, respectively, representing 0.29% of the cassava genome, were generated; of which 23 and 19 showed informative polymorphic patterns. Consequently, all identified informative polymorphic markers were used to genotype 200 F1 progeny plants. The genotypic data were then analyzed, and the results showed that 480 markers were distributed across 23 linkage groups (LGs) with total length of 1,334 centimorgans (cM). An analysis of QTL underlying the PT trait revealed that marker EME81 on LG 1 had significant associations (P < 0.0001) in all environments evaluated. Four candidate genes were identified and selected for gene expression analysis in the parents, and among F1 lines with high and low PT values. Significant differences were observed in relative expression of carbohydrate phosphorylase (CP) and starch synthase II (SSII) between high and low PT in 6-month-old cassava. We found CP and SSII genes to potentially control the PT trait. In addition, the marker EME81 was found to be a promising marker for specific PT trait selection in cassava populations, which should facilitate marker-assisted selection for desired PT traits.

Coordinated Regulation of Cold Induced Sweetening in Tetraploid Potato Families by Isozymes of UDP-Glucose Pyrophosphorylase and Vacuolar Acid Invertase

Past investigations have suggested that both UGPase and AcInv activities can be used as markers to screen genetically diverse potato clones for cold induced sweetening resistance (CIS-R). The goal of this study was to define their cooperative interaction in regulating sweetening. Inter- and intra-ploidy hybridizations of good (G) and poor (P) processing 24 or 48 chromosome potato clones were used to create 24 potato families. Potatoes were field grown and 460 progeny (≤20 each family) were stored for five months in the cold (4 C). Tubers from each progeny plant were evaluated for cold induced sweetening resistance (CIS-R) and correlated with the percentage of A-II isozymes of UDP-glucose pyrophosphorylase (UGPase; EC 2.7.7.9); and acid invertase activity (AcInv; EC 3.2.1.26). Each progeny was given a CIS-R score of 1–10 (1-most resistance, 10 least resistance). The families were grouped into four classes based on (1) high or low AcInv activity (low being a SA of 0.30 or less) (2) high or low percentage of A-II isozymes (low being 50% or less), and (3) CIS-R score. In high AcInv families, CIS-R was low regardless of the percentage of A-II isozymes present. In low AcInv activity families, there was a trend for average chip color to improve as the percentage of A-II isozymes increased from 0% to 40%. This increase in CIS-R in low AcInv families is likely due to the kinetic properties unique to the A-II forms of UGPase (principally UGP5) which limit the formation of sucrose via sucrose-6-phosphate synthase (SPS; EC 2.4.1.14). Lower concentrations of sucrose can lead to a decrease in reducing sugar production via vacuolar AcInv and lighter chip and fry colors. In selecting tetraploid parents, for the development of processing potato clones with improved CIS-R, it is recommended they have a basal AcInv SA of 0.30 or less and have A-II isozymes of UGPase.

Registration of WA‐HT1, a Camelina Line with Resistance to Residual Levels of ALS Inhibitor Herbicides

Camelina (Camelina sativa L. Crantz) is highly sensitive to soil residual levels of many acetolactate synthesis (ALS) inhibitor herbicides. Other crops with resistance to these herbicides have been developed through mutation. Development of camelina with this resistance would allow greater flexibility for the crop in rotation with other crops. The SM4 (sulfonylurea mutant 4) line, previously derived by mutagenesis, showed increased resistance to both imidazolinone and sulfonylurea herbicides. The mutation was controlled by a single semidominant gene and was derived in the ‘Cheyenne’ background. Progeny plants with good vigor from the SM4 variant were crossed to the plants from cultivar Calena, which has consistently performed well in Camelina trials the US Pacific Northwest. Lines from this cross that had good seed yields and were homozygous for the gene controlling resistance were advanced by pedigree selection at Washington State University. Selection for seedling vigor, seed yield, and oil content resulted in the F6–derived line WA‐HT1 (GP‐37, PI 683517). The WA‐HT1 line is severely stunted if specified field rates of imazamox (Beyond) herbicide is directly applied but is tolerant to residual levels of the herbicide encountered from carryover of previous applications. Use of the WA‐HT1 line will reduce the risk associated with growing camelina in crop rotations that use group 2 herbicides.

Genome-Wide Gene Expression Disturbance by Single A1/C1 Chromosome Substitution in Brassica rapa Restituted From Natural B. napus.

Alien chromosome substitution (CS) lines are treated as vital germplasms for breeding and genetic mapping. Previously, a whole set of nine Brassica rapa-oleracea monosonic alien addition lines (MAALs, C1-C9) was established in the background of natural B. napus genotype “Oro,” after the restituted B. rapa (RBR) for Oro was realized. Herein, a monosomic substitution line with one alien C1 chromosome (Cs1) in the RBR complement was selected in the progenies of MAAL C1 and RBR, by the PCR amplification of specific gene markers and fluorescence in situ hybridization. Cs1 exhibited the whole plant morphology similar to RBR except for the defective stamens without fertile pollen grains, but it produced some seeds and progeny plants carrying the C1 chromosome at high rate besides those without the alien chromosome after pollinated by RBR. The viability of the substitution and its progeny for the RBR diploid further elucidated the functional compensation between the chromosome pairs with high homoeology. To reveal the impact of such aneuploidy on genome-wide gene expression, the transcriptomes of MAAL C1, Cs1 and euploid RBR were analyzed. Compared to RBR, Cs1 had sharply reduced gene expression level across chromosome A1, demonstrating the loss of one copy of A1 chromosome. Both additional chromosome C1 in MAAL and substitutional chromosome C1 in Cs1 caused not only cis-effect but also prevalent trans-effect differentially expressed genes. A dominant gene dosage effects prevailed among low expressed genes across chromosome A1 in Cs1, and moreover, dosage effects for some genes potentially contributed to the phenotype deviations. Our results provided novel insights into the transcriptomic perturbation and gene dosage effects on phenotype in CS related to one naturally evolved allopolyploid.

Evaluation of F1 and BC1 hybrids of Lilium lancifolium × Asiatic hybrid ‘Chianti’ by morphological analysis and fluorescence in situ hybridization

ABSTRACTLilium lancifolium Thunb. exhibits wide genetic diversity and numerous genetic traits within progeny populations. Parent morphology affects the distribution and assortment of progeny phenotypes. In this study, morphological analysis and fluorescence in situ hybridization (FISH) were conducted for cross progeny (F1 and BC1). Results showed that F1-1 hybrids had greater plant height than the parents; however, backcross progeny plant height (group 1) was low. Leaf number in both groups was considerably low in F1 hybrid, although high in backcrossed plants. Flower number and days to flower opening were intermediate to those of the parents for F1 hybrids, yet low in BC1 progeny. In group 1, backcross progeny showed small bulb length; however, group 2 progeny showed large bulb length. Positive and negative correlations between the phenotypic traits of parents and progeny confirmed significant variations. According to FISH results, F1-1 and F1-2 hybrids distinctly exhibited nine and eight 45S rDNA loci which were same in position with 45S loci of the parents. In backcross progeny, eight 45S rDNA signals were detected in four BC1 progeny of group 1, while 10 signals were observed in all group 2 progeny, same with the L. lancifolium karyotype. Morphological analysis and FISH helped in scrutinising progeny to obtain hybrids with desirable characteristics.