Off-type Plants Research Articles

Comparative seed yields of lowland rice (Oryza sativa L.): evaluating seeds sources and fertilizers

Abstract The use of high-quality seeds from high-yielding rice varieties (HYV) is crucial for enhancing grain yield. Yet, the supply of certified seed meets only 57.3% of the total rice seed demand, leading some farmers to plant non-certified local rice seeds. A study examining the effects of seed sources and fertilization on seed yields was conducted in Bogor Village, Sukra District, Indramayu Regency during the Dry Season of 2019. The treatments consisted of two factors: A. Seed sources (Local non-certified seed (Local-NC), HYV non-certified seed (HYV-NC), and HYV-certified seed) and B. Fertilization methods (Recommended Fertilizer (RF), RF+BioF, RF+P as top dressing, and RF+N as top dressing). These were designed in a Complete Block Design with three replications. Results showed that Local-NC was more susceptible to BPH and RSB than HYV varieties. Additionally, Local-NC had the highest percentage of off-type plants and produced the lowest grain and seed yields. The addition of P or N fertilizer to RF during the heading stage notably improved the panicle number per hill, 1000-grain, seed yields and rendement. Our findings suggest that optimal rice seed yields can be achieved by planting HYV– certified seeds and applying either RF + 18 kg P ha−1 or RF + 11.5 kg N ha−1 as top dressing.

Efficiency of Biological Typing Methods in Maize Hybrid Genetic Purity Estimation.

A high level of genetic purity in crop varieties must be achieved and maintained for agronomic performance, encouraging investment and innovation in plant breeding and ensuring that the improvements in productivity and quality imparted by breeders are delivered to the consumer. Since the success of hybrid seed production is dependent upon the genetic purity of the parental lines, in this study, the experimental F1exp maize hybrid and its parental inbreeds were used as a model system to examine the discriminative power of morphological, biochemical and SSR markers for seed purity assay. The highest number of off-type plants was estimated by morphological markers. According to the comparison of prolamins and albumins banding patterns of parental and derived F1exp seeds, genetic impurities could not be detected. Molecular analysis detected two types of genetic profile irregularity. Beside its use for verifying varieties of maize, report on umc1545 primer pair ability to detect non-specific bands (i.e., off-types), in both the maternal component and F1exp, which is the first report on this issue yet, strongly supports the recommendation of this SSR marker use for more accurate and time-efficient maize hybrids and parental lines genetic pyrity testing.

SNP Genotyping for Purity Assessment of a Forage Oat (Avena sativa L.) Variety from Colombia

Single nucleotide polymorphism (SNP) markers have multiple applications in plant breeding of small grains. They are used for the selection of divergent parents, the identification of genetic variants and marker-assisted selection. However, the use of SNPs in varietal purity assessment is under-reported, especially for multi-line varieties from the public sector. In the case of variety evaluation, these genetic markers are tools for maintaining varietal distinctness, uniformity and stability needed for cultivar release of multi-line or pure-line varieties of inbred crops. The objective of this research was to evaluate the purity and relationships of one original (AV-25) and two multi-line sub-populations (AV25-T and AV25-S) of the inbreeding species, oats (Avena sativa L.). Both sub-populations could be useful as forages in the central highland region of Colombia (>2000 masl), such as in the departments of Boyacá and Cundinamarca, even though they were derived from an original composite mixture widely used in the mountainsides of the southern department of Nariño named Avena 25. Representative single plant selections (SPS) from the two sub-populations were grown together with SPS harvests from off-type plants (early and late) and plants from the original AV25 composite mixture, to determine their genetic similarity. Plants were genotyped by DNA extraction of a plateful of 96 individual plant samples and SNPs were detected for an Illumina Infinium 6K Chip assay. The data were used for the analysis of genetic structure and population relationships. The grouping observed based on the genetic data indicated that AV25-T and AV25-S were homogeneous populations and somewhat divergent in their genetic profile compared to the original AV25-C mix. In addition, to the two commercial, certified oat varieties (Cajicá and Cayuse) were different from these. The early and late selections were probable contaminants and could be discarded. We concluded that the use of SNP markers is an appropriate tool for ensuring genetic purity of oat varieties.

Rapid Detection of Hybrid Maize Parental Lines Using Stacking Ensemble Machine Learning

Hybrid maize seed production is a relatively complex task due to the coexistence of three distinct types of maize plants in the field: female, male, and contaminant/off-type plants. Female and contaminant/off-type plants’ tassels should be removed immediately following flowering initiation, while male tassels should be retained to allow cross-pollination between male and female plants. Therefore, development of an intelligent tassel classification system is deemed critical for hybrid purity decision-making. The research’s primary contribution is the integration of two widely used transfer learning architectures, Inception V3 and SqueezeNet, with stacking ensemble machine learning using four algorithms (logistic regression, support vector machine, random forest, and k-nearest neighbors) for rapid classification of tassel images. Tenfold cross-validation was used to evaluate the model performance. Cloud computing was also investigated using EfficientNet to compare the predictive performance of the models. The models’ performance was assessed using four metrics: accuracy, AUC, precision, and recall. The results depicted an appropriate developed model that properly distinguished male, female, and contaminant plants. The integration of the model with machine learnings (logistic regression, SVM, random forest, and KNNs) enables rapid recognition of off-type plants even though it is operated by personnel with limited skills of seed technology on ideotype recognition. Among all the evaluated CNN architecture and stacking models, Inception V3-embedded images with logistic regression metaclassifier outperformed other models with accuracy of about 98%. SqueezeNet and EfficientNet provided comparable results for consistent tassel classification with slightly lower performance measures. The model was also subjected to a multidimensional scaling (MDS) analysis to investigate and comprehend misclassification. Male and female plants are clearly distinguished by MDS, but female and off-type/contamination plants are ambiguous. This indicates that the prediction errors were caused by highly similar data features among female and off-type images. The developed modern plant phenotyping model can be used to assist breeders/technicians in maintaining the quality of large-scale hybrid maize seed production activities in Indonesia.

Masking technique based attention mechanism for off-type identification in plants

Off-type plants, or other distinct varieties of the same plant, need to be detected and removed at early stage from the fields to preserve the genetic integrity and significant traits of a given plant variety. At present, these off-type plants are manually identified in the cultivation fields through morphological analysis of leaves. This method is time-consuming and involves skilled labor to define the off-type plant. Hence, masking technique based attention mechanism is proposed for identifying the off-type from the leaf images captured in the cultivation fields. The proposed method recognizes the plant variety by locating and visualizing the prominent parts of the leaf which is similar to the human visual attention mechanism. When the prominent parts of the leaf image are masked, there is a significant drop in the class probability of the convolutional network. This reflects the importance of such prominent parts which directly account for its variety. An attention module is designed using neural networks which focuses on such significant regions and improves the performance of the network. The proposed method is tested on a field image dataset consisting of 1235 images of Sunflower leaves and achieves the highest mean accuracy of 98.25% in identifying the plant variety.

A decision support system for hybrid corn classification

High yielding corn is primarily derived from a cross-pollination among superior appearing male and female plants. Cross-pollination is closely linked at the tasseling/flowering stage, marked by the emergence of tassel for 5-10 days. With the advancement of machine learning, there are opportunities to apply deep learning models to control the purity of plants. The research aims to develop a decision support system based on deep learning to enable earlier identification and removal of contamination/off-type plants during seed production. The datasets containing 1,587 tassel images taken by high resolution camera. The results of the training and the validation sequence indicated a highly correlated accuracy score. A quite contrasting tassel morphology makes it easier for the model to distinguish on and off-type plants. The loss value during the training and the validation stages was 0.05 and 0.1 respectively. A stand-alone graphical user interface (GUI) was deployed to support the early detection of tassels in the field. This tool can be used to support national corn seed production programs.

Effects of the in vitro behavior of micropropagated plants on the stability of variegation in Yucca gloriosa, Phormium tenax, and Cordyline australis cultivars

Cultivars with variegated foliage could be difficult to obtain in large-scale production of true-to-type plants. To determine the micropropagation potentialities of ornamental variegated monocotyledons in an industrial and commercial context, to define the stability of their variegated phenotypes, and to understand how and when off-type plants appear, the shoot tips of a variegated cultivar of three different species : Yucca gloriosa ‘Variegata’, Phormium tenax ‘Jessie’ and Cordyline australis ‘Pink Passion’ were introduced in vitro for propagation. The propagation rates and the variegation stability were estimated by separately monitoring each plant obtained during the several successive subcultures. During the in vitro process, samples were periodically fixed and studied by staining histological sections of the shoot tips. Leaf tissues were studied by light and confocal microscopy.After three-four subcultures, the multiplication rates obtained were stabilized at around 2.5–3 for Yucca, 1.4–1.7 for Phormium, and 1.2–1.7 for Cordyline. The number of off-type plants obtained after six multiplication cycles was around 10 % for Yucca, 25 % for Phormium and 60 % for Cordyline. The histology study showed that the axillary bud meristems (AxM) are totally (Yucca and Cordyline) or partially (Phormium) repressed by shoot apical meristem (SAM) in PGR-free medium. In the presence of BAP or BAP and NPA, only AxM were observed for Yucca, Phormium mainly developed AxM and some adventitious bud meristems (AdM), and Cordyline developed both AxM and AdM. The leaf section observations revealed that the three variegated cultivars turned out to be three periclinal chimeras.This histological study carried out on these cultivars highlights major differences in the development and in vitro multiplication behavior of three different genera belonging to the order Asparagales (clade monocotyledons). The variegation stability of these chimeric cultivars depends on their propensity to propagate by adventitious meristems.

Plant Genome Editing and the Relevance of Off-Target Changes.

Site-directed nucleases (SDNs) used for targeted genome editing are powerful new tools to introduce precise genetic changes into plants. Like traditional approaches, such as conventional crossing and induced mutagenesis, genome editing aims to improve crop yield and nutrition. Next-generation sequencing studies demonstrate that across their genomes, populations of crop species typically carry millions of single nucleotide polymorphisms and many copy number and structural variants. Spontaneous mutations occur at rates of ∼10-8 to 10-9 per site per generation, while variation induced by chemical treatment or ionizing radiation results in higher mutation rates. In the context of SDNs, an off-target change or edit is an unintended, nonspecific mutation occurring at a site with sequence similarity to the targeted edit region. SDN-mediated off-target changes can contribute to a small number of additional genetic variants compared to those that occur naturally in breeding populations or are introduced by induced-mutagenesis methods. Recent studies show that using computational algorithms to design genome editing reagents can mitigate off-target edits in plants. Finally, crops are subject to strong selection to eliminate off-type plants through well-established multigenerational breeding, selection, and commercial variety development practices. Within this context, off-target edits in crops present no new safety concerns compared to other breeding practices. The current generation of genome editing technologies is already proving useful to develop new plant varieties with consumer and farmer benefits. Genome editing will likely undergo improved editing specificity along with new developments in SDN delivery and increasing genomic characterization, further improving reagent design and application.

Comparative Study on some Pure Successive Maintained Nuclei (Foundation Seed) of Giza 95 Cotton Cultivar and its Corresponding Handled one’s in General Cultivation.

Four successive pure maintained nuclei (N) and four handled farmer's seeds (F) of Giza 95 Egyptian cotton cultivar were used to evaluate the changements that might occur in earliness, yield ,fiber quality and genetic constitution of the cultivar after handling the seeds by the farmers. Two field experiments were carried out at Sids Agric. Res. Station, throughout growing seasons 2017 and 2018. Genotypes mean squares were significant and/or highly significant for seed cotton yield, lint yield, earliness index and yarn strength in both seasons and combined analysis. The greatest amount of differences among the studied strains were mainly due to the variances among the farmer's seeds and the interaction (N vs F), for these characters indicating farmer seeds might get genetic imperfection due to mechanical mixture or out-crossing by off-type plants. The interactions of genotypes by environments (G x E) were insignificant for all studied characters except boll weight and fiber fineness. Regarding mean performances, the results indicated that the pure nuclei strains surpassed the farmer's ones for most studied traits. The older farmer's strains (G.95/2014) exhibited lower mean performance estimates for most studied yield traits over the two environments and it’s combined data. Also, nuclei seeds gave the best performances for most fiber properties compared with the farmer's ones. Seed cotton yield in both nuclei and farmer's strains was positively and significantly related with earliness index and fiber fineness suggested that any changes when appear in these characters may be correlate with decrease of seed cotton yield or any deterioration appeared.

Evaluation of Clonal Uniformity in Six Superior Cacao Clones Based on SSR Marker

<p><em>Propagation of cacao plants is generally carried out vegetatively. Therefore, plants that are clonally propagated should be genetically uniform. Genetic uniformity in cacao clones is also very important information for germplasm conservation and in obtaining pure parental crosses. Evaluation of genetic uniformity can be seen through analysis using SSR markers. This study aimed to determine the genetic uniformity in six cacao clones using SSR markers. This experiment was conducted at IIBCRI Integrated Laboratory in Sukabumi and Plant Molecular Biology Laboratory, IPB Bogor, from September 2015 to December 2016. Six cacao clones used (TSH 858, TSH 908, ICS 13, PA 300, GC 7 and UIT) are from Kalitelepak experimental station of PTPN XII, Genteng District, Banyuwangi, East Java. Ten samples were taken randomly to represent cacao clones. DNA amplification was carried out using 12 SSR markers. The result showed that 12 SSR markers generated 45 alleles with the number of alleles per locus was 3-4 alleles. The polymorphic information content (PIC) ranges from 0.37</em>–<em>0.67, which are identied as very informative molecular analysis </em><em>in identifying the genetical uniformity of the evaluated cacao population. Six SSR loci generated variant alleles within both the TSH 858 and UIT clones, indicating there are off-type plants in these two samples. Clonal uniformity were detected for samples of the GC 7, ICS 13, PA 300 and TSH 908 clones. On the other hand, 8.33% of evaluated samples within the TSH 858 and UIT clones were off-type plants.</em></p>

Elimination of Grapevine leafroll associated virus-3, Grapevine rupestris stem pitting associated virus and Grapevine virus A from a Tunisian Cultivar by Somatic Embryogenesis and Characterization of the Somaclones Using Ampelographic Descriptors.

Prospecting of local grapevine (Vitis vinifera L.) germplasm revealed that Tunisia possesses a rich patrimony which presents diversified organoleptic characteristics. However, viral diseases seriously affect all local grapevine cultivars which risk a complete extinction. Sanitation programs need to be established to preserve and exploit, as a gene pool, the Tunisian vineyards areas. The presence of the Grapevine leafroll associated virus-3 (GLRaV-3), Grapevine stem pitting associated virus (GRSPaV) and Grapevine virus A (GVA), were confirmed in a Tunisian grapevine cultivar using serological and molecular analyses. The association between GRSPaV and GVA viruses induces more rugose wood symptoms and damages. For this reason the cleansing of the infected cultivar is highly advisable. Direct and recurrent somatic embryos of cv. ‘Hencha’ were successfully induced from filament, when cultured on Chée and Pool (1987). based-medium, enriched with 2 mg 1−1 of 2,4-dichlorophenoxyacetic acid and 2.5 mg 1−1 of Thidiazuron, after 36 weeks of culture. After six months of acclimatization, RT-PCR carried on 50 somaplants confirmed the absence of GVA, GRSPa-V as well as GLRaV-3 viruses in all somaplants. Ampelographic analysis, based on eight OIV descriptors, was carried out on two years acclimated somaplants, compared to the mother plant. Results demonstrated that the shape and contours of 46 somaclones leaves are identical to mother plant leaves and four phenotypically off-type plants were observed. The healthy state of 100% ‘Hencha’ somaclones and the high percentage of phenotypically true-to-type plants demonstrate that somatic embryogenesis is a promising technique to adopt for grapevine viruses elimination.

How an improved sorghum variety evolves in a traditional seed system in Mali: Effects of farmers’ practices on the maintenance of phenotype and genetic composition

In Africa, it is mostly the informal seed system that ensures farmers’ seed supply. This is partly because the formal seed systems are not always effective in meeting demand for new seed varieties. Sometimes informal seed recycling and exchange of improved sorghum varieties will take place alongside formal initiatives, as is the case in southern Mali. Focusing on one particular village in the Dioïla district, we analyze the efficacy of farmers’ strategies for preserving varietal seed purity and genetic integrity of an improved inbred-line (Soumba variety). Six seed lots of Soumba, recycled for two to six years by farmers using different practices, were collected and assessed in on-station trials in order to compare their agronomic performance and phenotypic purity (off-type plant frequencies) with control versions of the variety. Additionally, 30 panicle samples were randomly collected from five farmer fields sown with recycled Soumba and assessed for phenotypic purity in a progeny nursery and investigated for molecular diversity using 12 SSR markers. A total of 150 panicles from five other non-Soumba varieties were collected in the village in order to investigate eventual gene flow and its potential genetic consequences for the Soumba variety. In fields sown with recycled Soumba seed, between 2% and 14% of plants showed phenotypic deviations from the typical Soumba variety. The progeny nursery and SSR marker analysis verified the presence of the off-type plants observed in the field. The STRUCTURE program revealed admixtures with other varieties in 23% of Soumba plants, confirming the presence of gene flow. Gene diversity values in Soumba samples ranged from 0.006 for the commercial sample to 0.257 for recycled samples. Introgression and contamination were best minimized when (1) farmers had received specific training in seed production, (2) they could take advantage of isolated fields and (3) they could practise true-to-type panicle selection. Farmers were generally able to maintain the phenotype, as well as sustain or even improve yield performance of their Soumba variety while at the same time genetically enriching their seed stock.

Morphological and genetic characterization of off-type rice plants collected from farm fields in Korea

Off-type rice plants occurring in farm fields cause yield loss due to competition with cultivated rice, in addition to hindering field management and harvest work. This study aimed to observe the agronomic characteristics and trace the origins of off-type rice plants using molecular markers. A total of 116 rice accessions, comprising 35 off-type plants collected from Korean farm fields, 19 Korean commercial cultivars, 12 Korean land races, and 50 weedy rice collections, were phenotyped and genotyped using selected SSR and Subspecies Specific (SS)-STS markers. The results showed that the plant height, culm length, and leaf length of off-type rice plants were larger than those of cultivated rice, which is the typical phenotype of weedy rice. However, off-type plants were highly sterile, as opposed to weedy rice, which were highly fertile. Genotype analysis with SSR and SS-STS markers revealed that off-type rice plants were heterozygous at most of the tested marker loci, suggesting that the off-type rice plants may have originated from natural outcrossing. The genotypes of off-type rice plants were closely related to both weedy and cultivated rice, and the phylogenetic analysis revealed that the relationship of the clustered group of offtype rice plants is intermediate between Indica type weedy rice and Japonica type commercial varieties. These results suggested that off-type rice plants collected in Korean farm fields might have originated from natural outcrossing between Indica type weedy rice and the cultivated Japonica type commercial varieties.

Stable progeny production of the amphidiploid resynthesized Brassica napus cv. Hanakkori, a newly bred vegetable

Resynthesized Brassica napus cv. Hanakkori (AACC, 2n=38) was produced by cross-hybridization between B. rapa (AA, 2n=20) and B. oleracea (CC, 2n=18) as a new vegetative crop. Many studies have provided evidences for the instability and close relationship between A and C genome in the resynthesized B. napus cultivars. In fact, seed produced to obtain progeny in Hanakkori had unstable morphological characters and generated many off-type plants. In this study, we investigated the pollen fertility, chromosome number, structure, and behavior linked to various Hanakkori phenotypes to define factors of unstable phenotypic expression in the progeny. Hanakkori phenotypes were categorized into five types. The results of pollen fertility, chromosome number, and fluorescence in situ hybridization analysis for somatic mitosis cells indicated that the off-type plants had lower pollen fertility, aberrant chromosome number, and structures with small chromosome fragments. Observation of chromosomes at meiosis showed that the meiotic division in off-type plants led to appreciably higher abnormalities than in on-type plants. However, polyvalent chromosomes were observed frequently in both on- and off-type plants in diplotene stage of meiosis. We assume that the unstable morphological characters in resynthesized progeny were the result of abnormal division in meiosis. It results as important that the plants of normal phenotype, chromosome structure and minimized abnormal meiosis are selected to stabilize progeny.

Sunflower crop-wild hybrids: Identification and risks

Wild sunflower, Helianthus annuus, is an open-pollinated species that can be a major weed in several crops. If it hybridizes with cultivated sunflower the following generations can generate crop-wild hybrids that could evolve into invasive populations. The objective of this study was to morphologically characterize F1 hybrids between inbred lines and wild sunflower, their F2, BC1 and BC2 progenies with domestic sunflower to assess the risk of these plants evolving into invasive biotypes. Crop-wild hybrids were easily identified as off-type plants. F1 plants were taller, branched with several heads, smaller disks and phyllaries, stigma and pale anthocyanins, and a longer flowering period compared to cultivated sunflower. None of the F2 plants were similar to wild sunflower plants, but morphologically closer to the cultivated materials. These results showed the improbability that crop-wild off-type plants give rise to plants morphologically similar to wild sunflowers and therefore the risk of developing invasive populations by their introduction.

Molecular genetic analysis of off-type plants identified from normal F1 hybrid cultivars of sweet pepper (Capsicum annuum L.)

SummaryOff-type plants occasionally appear when growing F1 hybrid cultivars of sweet pepper (Capsicum annuum L.). In this study, possible genetic factors responsible for the appearance of off-types were evaluated using two off-type sweet peppers selected out of 120 F1 hybrids. The general morphology of off-type plants showed a stunted stature, narrow leaf shape, and small round-shaped fruits. We hypothesised that these off-type plants might have arisen by inadvertent self-pollination of maternal parental lines, since most sweet pepper F1 hybrids are known to be produced by hand-emasculation. Indeed, none of the sweet pepper cultivars analysed in this study contained male-sterile cytoplasm, confirming that cytoplasmic male-sterility was not used during F1 hybrid seed production. If the off-type plants were derived from self-pollination of maternal lines, the genetic make-up of the off-type plants should be different from that of normal F1 hybrids. However, the RAPD and SSR marker amplification profiles of off-type and normal F1 hybrids showed no polymorphism, whereas one RAPD and five polymorphic SSR markers were identified among five other F1 sweet pepper cultivars, indicating that the genetic make-up of the off-type and normal F1 hybrids were almost identical. Furthermore, two SSR markers that showed heterozygosity in both off-type and normal F1 hybrids, segregated in the self-pollinated progenies of both off-type and normal F1 hybrids, indicating that the off-type plants were not maternal inbred lines. Taken together, these results suggest that the off-type F1 sweet pepper plants could have arisen due to other environmental factors or by infection with an unknown pathogen.

SOMACLONAL VARIATION IN MICROPROPAGATED TULIPS AS A SOURCE OF NOVEL GENOTYPES – FIELD AND MOLECULAR CHARACTERISTIC

Somaclonal variation (SV) was evaluated in tissue-culture (TC) derived plants of the tulip cultivar 'Giewont' and genotype Bs6, the mutant selected from among the micropropagated plants of the cultivar 'Blue Parrot' in 2004. The plant material of both genotypes derived from the long-term cultures maintained in vitro for a period of 2, 4 or 6 years. The plants were planted outdoors in an insect-proof tunnel in 1999-2004. Phenotypic evaluation was done during the subsequent years of cultivation, in 2006 and 2007. The plants of the mutant Bs6 have parrot flowers which are 1.5-2 cm longer with stems which are 7-10 cm longer than the original 'Blue Parrot' plants. Further the flower colour changed from purple-violet to red-purple. In 2008, selected Bs6 true-to-type plants have given start new cultivar 'Agalia'. SV frequency in 'Giewont' and Bs6 ranged from 5.9 to 15.3%, including 1.5-6.8% SV frequency resulted from instable variants, characterized with a flower fasciation or a partly green tepal, accreted with a last leaf. Some off-type plants of genotype Bs6 had minor changes, i.e. the flower shape was altered to non-parrot type. Variants with major changes, having highly malformed flowers, occurred regularly in both genotypes. They had always leaves with thicken, vitreous venation. Such leaf malformation was also found within juvenile plants. Similar variants were previously observed in TC-derived plants of tulip 'Prominence'. DNA analysis of 'Giewont', Bs6 and 'Prominence' variants (both the flowering and juvenile plants) with ISSR (inter simple sequence repeats) technique confirmed that the leaf malformation resulted from genetic changes. The results indicate that the trait of leaf thicken, vitreous venation can be considered as a morphological marker for early detecting the major genetic changes within juvenile plant material.

Gene flow between cultivated sunflower and Helianthus petiolaris (Asteraceae)

Helianthus petiolaris (Asteraceae) native to North America has naturalized in Argentina. The extensive overlapping with sunflower crop regions, the coincidence of life cycles and the common pollinators facilitate interspecific crosses with sunflower, H. annuus var. macrocarpus. To estimate the occurrence of crop-to-wild and wild-to-crop gene flow, off-type plants in progenies of pure stands of both species flowering in coincidence and the presence of crop alleles in H. petiolaris populations were investigated in 26 wild populations and nine crop fields. Morphological traits and RAPD markers were used to attempt hybrid characterization. Off-type individuals were found in frequencies of 0.5 and 0.3% among crop progenies and wild populations, respectively. Off-type plants showed intermediate values for metric morphological traits and low fertility traits. Some off-type plants proved to carry crop alleles based on molecular analysis. The average frequency of cultivar-marker introgression across the wild populations was very low (0.02). Although observed hybridization rates seem to be low, the extension of crop-wild overlapping in Argentina make hybrid formation a noticeable process. Therefore, the new sunflower varieties and eventually GM varieties would transfer their traits through pollen flow and they would persist in H. petiolaris populations.

Genetic characterization of the origin of offtype plants in maize inbred lines

Genetic characterization of the origin of offtype plants in maize inbred lines

Altered Response to Biotic and Abiotic Stress in Tissue Culture-Induced Off-Type Plants of East African Highland Banana (Musa AAA East Africa)

Altered Response to Biotic and Abiotic Stress in Tissue Culture-Induced Off-Type Plants of East African Highland Banana (Musa AAA East Africa)