Interspecific Hybrid Progenies Research Articles

Selection of Saccharum spp. × Saccharum spontaneum progeny for sugar and biomass traits

ABSTRACT This study evaluated an interspecific hybrid (Saccharum spp. × S. spontaneum) population with the aim of developing germplasm for use in both sugar and bioenergy (biomass) production. Specific objectives were to determine the genetic variability and heritability among the interspecific hybrid progenies for traits of economic importance and to use the Best Linear Unbiased Predictions (BLUPs) to determine their genotypic values. The 46 interspecific hybrids used in this study originated from crossing commercial sugarcane cultivars (UT5, F152, and KK07–559) as female and S. spontaneum clones (THS98–41, THS98–91, THS98–95, THS98–94, and THS97–51) as male parents. There were significant residual variances, attributed to the small plot size, but the juice quality traits were measured with relatively higher precision than other traits. Selection recommendations varied for different traits, suggesting selection pressure could be moderate to high for juice quality traits and moderate for yield-related traits. No hybrid genotypes were found to outperform cultivar parents for traits such as commercial cane sugar and low fiber, necessitating further germplasm enhancement for improvement of varieties destined for sugar production. On the contrary, transgressive segregation was observed for cane yield and other traits influencing biomass yield. The production potential of these hybrids could be tested in larger plots across multiple locations.

Genetic control of growth and wood traits in Eucalyptus camaldulensis × E. urophylla and reciprocal hybrids

Eucalyptus camaldulensis (Ec) × E. urophylla (Eu) and reciprocal hybrid crosses were evaluated for growth and wood traits at four years at West Godavari Dt, Andhra Pradesh State located in Southern India, in relation to full and half sib progenies of pure E. camaldulensis maternal parents. Interspecific hybrid progenies had 16.6% higher average growth and 8% lower average wood basic density than pure species progeny. The interspecific hybrid progenies fibre properties viz., fibre length, fibre width, lumen diameter and fibre wall thickness were comparably higher than pure species progeny and check clones. The Ec × Eu crosses had comparable growth and wood basic density as the reciprocal hybrid progeny, but fibre length was 3.4% higher than the Eu × Ec hybrids, the values being statistically significant at p<.001 level. Analysis of variance of data was done using the 20th Edition of Genstat software (VSNi). Growth and fibre traits showed a positive relation but wood basic density showed a negative correlation (r = -0.94). There was a positive correspondence between the General Combining Ability (GCA) of pure E. camaldulensis maternal parents and their General Hybridizing Ability (GHA) for growth. The study showed that parents of Ec and Eu could be used to improve the growth and fibre traits in interspecific hybrids.

Genetic mapping of the pear scab resistance gene Vnlf using a pseudo-BC3 population derived from Japanese pear cultivars and European pear ‘La France’

Pear scab disease caused by Venturia nashicola is one of the most serious diseases of Asian pears. To facilitate the breeding of scab-resistant cultivars, we mapped and developed markers for a resistance gene from the European pear (Pyrus communis) cultivar ‘La France’. By using a pseudo-backcross strategy to introduce genes from ‘La France’ into Japanese pear (P. pyrifolia) cultivars, we developed a mapping population from a cross between Japanese pear ‘Akiakari’ and interspecific hybrid progeny line 537–14. The individuals in the mapping population were evaluated for resistance by inoculation testing in 2020 and 2021. The segregation ratio of resistant to susceptible individuals was 1:1, indicating that resistance is inherited as a single dominant gene, which we named Vnlf. A genetic linkage map was constructed using single-nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers. On the basis of the genetic map of 537–14, we narrowed down the putative region carrying Vnlf to 959 kb on chromosome 2 between SNPs Chr2_20220913 and Chr2_21180341. To facilitate marker-assisted selection in Japanese pear breeding programs, we developed SSRs closely linked to Vnlf, one of which (LFA02a09) showed complete linkage to the resistance phenotype in an inoculation test of 175 individuals. These linked markers will enable introgression of Vnlf into breeding materials without the need for inoculation tests and will facilitate pyramiding Vnlf with other scab resistance loci.

Screening of Psidium species and their interspecific hybrid progenies for resistance to Fusarium oxysporum f. sp. psidii and southern root-knot nematode

Screening of Psidium species and their interspecific hybrid progenies for resistance to Fusarium oxysporum f. sp. psidii and southern root-knot nematode

Characteristics and Fitness Analysis through Interspecific Hybrid Progenies of Transgenic Brassica napus and B. rapa L. ssp.

Interspecific hybridization between transgenic crops and their wild relatives is a major concern for transgene dispersal in the environment. Under controlled conditions, artificial hand pollination experiments were performed in order to assess the hybridization potential and the fitness of interspecific hybrids between Brassica rapa and genetically modified (GM) Brassica napus. Initially, six subspecies of B. rapa were hybridized with GM B. napus through hand pollination. In the resulting F1 hybrids, the combination of B. rapa ssp. narinosa (♀) × GM B. napus (♂) had the highest crossability index (16.9 ± 2.6). However, the F1 selfing progenies of B. rapa ssp. rapa (♀) × GM B. napus were found to be more effective in producing viable future generations with the highest crossability index (1.6 ± 0.69) compared to other subspecies. Consequently, they were used for the generation of F2 and F3 progenies. The 18 different morphological characteristics among the parental cross-combinations and F1 hybrid progenies were measured and visualized through hierarchical clustering. Different generations were found to be grouped based on their different morphological characteristics. The chromosome numbers among the interspecific hybrids ranged from 2n = 29 to 2n = 40. Furthermore, the SSR markers revealed the presence of genomic portions in the hybrids in comparison with their parental lines. There is a high possibility of transgene flow between GM B. napus and B. rapa. The study concluded that the interspecific hybrids between B. napus and B. rapa can be viable and can actively hybridize up to F3 generations and more. This suggests that the GM B. napus can disperse the transgene into B. rapa, and that it can pass through for several generations by hand pollination in a greenhouse environment.

Chromosome characterization and physical mapping of 18S rDNA in Lilium longiflorum originated interspecific hybrids using combined genomic and fluorescent in situ hybridization

This study was aimed to differentiate parental genomes, examining intergenomic composition, and mapping mitotic metaphase chromosomes by localizing parental and 18S rDNA probes in seven interspecific hybrid progenies that originated from Lilium longiflorum. Since single method of in situ hybridization has been widely used in interspecific lily breeding, while in this study, flow cytometry was used in conjunction with genomic and fluorescent in situ hybridization to determine the genomic contribution of each parent to the interspecific progenies. A significant variation was observed in the DNA content, chromosome length, and 18S loci in F1 as compared to the female and male parents. L. longiflorum showed nearly two times higher DNA content than the male parents and L. longiflorum × Asiatic progenies, but eight times higher than L. longiflorum × L. hansonii. Genomic in situ hybridization results revealed that both female and male parents contributed an equal number of chromosomes to their interspecific F1 offspring. Fluorescent in situ hybridization mapping revealed that 18S rDNA had 8, 6 and 7 loci in L. longiflorum parents, i.e., White heaven, Bright tower, and White tower, respectively, whereas each Asiatic cultivar and L. hansonii used as male showed 8 and 12 loci respectively. Interspecific progenies showed 8 and 7 loci in LA, and 10–11 in LM hybrids. These cytogenetic results implied equal genetic and chromosomal contribution from both parents to their intergenomic progenies. Therefore, this combined cytogenetic method has the potential to be genome specific and time-saving approach in lily breeding that could determine the status of hybrids and their genomic origin while achieving physical mapping and detecting genes in different genomes.

Rapid Creation of Interspecific Hybrid Progeny to Broaden Genetic Distance through Double Haploid (DH) Inducer in Brassica napus.

Interspecific hybridization of rapeseed is an important way to innovate breeding resources. This research used Brassica napus and Brassica rapa for artificial synthesis interspecific hybridization of F1. The F1 self-fruiting rate was particularly low. By comparing the fertilization rate and seed setting rate of nine crosses and selfing combinations of interspecific hybrid progeny F1 and control B. napus, the results proved that the genetic stability of egg cells was greater than that of sperm cells, so the F1 could get seed by artificial pollination with other normal pollen. Based on these results, interspecific maternal inbred offspring (induced F1) from egg cells was obtained by emasculation and pollination with the pollen of DH inducer Y3380. It was found through morphological analysis, flow cytometry identification, and meiotic observation of induced F1, the plants had most normal fertile tetraploid and the meiosis was normal. The FISH results showed that the induced F1 were B. napus (2n = 4x = 38, AACC), 20 A and 19 C chromosomes. The results of SNP chip detection and genetic cluster analysis found that the genetic variation between interspecies could be preserved or broadened in the induced F1. The use of DH inducer created special breeding resources for interspecific hybridization and distant hybridization of rapeseed while shortening time, improving efficiency, and providing a new insight into innovate breeding resources.

Performance of fatty acid composition, iodine value, carotene content, height and height increment of oil palm interspecific hybrids

A total of sixteen oil palm interspecific hybrid progenies were evaluated for their fatty acid composition, iodine value, carotene content, height and height increment at Malaysian Palm Oil Board (MPOB) Bagan Datuk, Malaysia. Based on the results, unsaturated fatty acids were higher with a range of 60% compared to current breeding materials. Iodine value showed a considerable amount of the oil palm interspecific hybrid which was around 65. Carotene among some individuals showed an outstanding value of 3424 ppm. Height and height increment showed lower value than current breeding materials with an average 0.17 m height increment per year. Heritability values showed that the genetic component gave higher influence towards height and height increment while the fatty acid composition and carotene content were largely influenced by the environment.

Phenotype study of multifoliolate leaf formation in Trifolium alexandrinum L.

BackgroundThe genus Trifolium is characterized by typical trifoliolate leaves. Alterations in leaf formats from trifoliolate to multifoliolate, i.e., individual plants bearing trifoliolate, quadrifoliolate, pentafoliolate or more leaflets, were previously reported among many species of the genus. The study is an attempt to develop pure pentafoliolate plants of T. alexandrinum and to understand its genetic control.MethodsThe experimental material consisted of two populations of T. alexandrinum with multifoliolate leaf expression, i.e.,interspecific hybrid progenies of T. alexandrinum with T. apertum, and T. alexandrinum genotype Penta-1. Penetrance of the multifoliolate trait was observed among multifoliolate and trifoliolate plant progenies. In vitro culture and regeneration of plantlets from the axillary buds from different plant sources was also attempted.ResultsThe inheritance among a large number of plant progenies together with in vitro micro-propagation results did not establish a definite pattern. The multifoliolate leaf formation was of chimeric nature, i.e., more than one leaf format appearing on individual branches. Reversal to normal trifoliolate from multifoliolate was also quite common. Penetrance and expression of multifoliolate leaf formation was higher among the plants raised from multifoliolate plants. Multifoliolate and pure pentafoliolate plants were observed in the progenies of pure trifoliolate plants and vice-versa. There was an apparent increase in the pentafoliolate leaf formation frequency over the years due to targeted selection. A few progenies of the complete pentafoliolate plants in the first year were true breeding in the second year. Frequency of plantlets with multifoliolate leaf formation was also higher in in vitro axillary bud multiplication when the explant bud was excised from the multifoliolate leaf node.ConclusionNumber of leaflets being a discrete variable, occurrence of multifoliolate leaves on individual branches, reversal of leaf formats on branches and developing true breeding pentafoliolates were the factors leading to a hypothesis beyond normal Mendelian inheritance. Transposable elements (TEs) involved in leaf development in combination with epigenetics were probably responsible for alterations in the expression of leaflet number. Putative TE’s movement owing to chromosomal rearrangements possibly resulted in homozygous pentafoliolate trait with evolutionary significance. The hypothesis provides a new insight into understanding the genetic control of this trait in T. alexandrinum and may also be useful in other Trifolium species where such observations are reported.

A hybrid sterile locus leads to the linkage drag of interspecific hybrid progenies

Interspecific hybridization plays an important role in rice breeding by broadening access to desirable traits such as disease resistance and improving yields. However, interspecific hybridization is often hindered by hybrid sterility, linkage drag, and distorted segregation. To mine for favorable genes from Oryza glaberrima, we cultivated a series of BC4 introgression lines (ILs) of O. glaberrima in the japonica rice variety background (Dianjingyou 1) in which the IL-2769 (BC4F10) showed longer sterile lemmas, wider grains and spreading panicles compared with its receptor parent, suggesting that linkage drag may have occurred. Based on the BC5F2 population, a hybrid sterility locus, S20, a long sterile lemma locus, G1-g, and a new grain width quantitative trait locus (QTL), qGW7, were mapped in the linkage region about 15 centimorgan (cM) from the end of the short arm of chromosome 7. The hybrid sterility locus S20 from O. glaberrima eliminated male gametes of Oryza sativa, and male gametes carrying the alleles of O. sativa in the heterozygotes were aborted completely. In addition, the homozygotes presented a genotype of O. glaberrima, and homozygous O. sativa were not produced. Surprisingly, the linked traits G1-g and qGW7 showed similar segregation distortion. These results indicate that S20 was responsible for the linkage drag. As a large number of detected hybrid sterility loci are widely distributed on rice chromosomes, we suggest that hybrid sterility loci are the critical factors for the linkage drag in interspecific and subspecific hybridization of rice.

Eastern Filbert Blight Resistance in American and Interspecific Hybrid Hazelnuts

Eastern filbert blight (EFB), caused by the fungus Anisogramma anomala, is a primary limitation to european hazelnut (Corylus avellana) cultivation in eastern North America. American hazelnut (Corylus americana) is the endemic host of A. anomala and, despite its tiny, thick-shelled nuts, is a potentially valuable source of EFB resistance and climatic adaptation. Interspecific hybrids (Corylus americana × C. avellana) have been explored for nearly a century as a means to combine EFB resistance with wider adaptability and larger nuts. Although significant progress was made in the past, the genetic diversity of the starting material was limited and additional improvements are needed for expansion of hazelnut (Corylus sp.) production outside of Oregon, where 99% of the U.S. crop is currently produced. Our objective was to determine if C. americana can be a donor of EFB resistance. We crossed 29 diverse EFB-resistant C. americana accessions to EFB-susceptible C. avellana selections (31 total progenies) to produce 2031 F1 plants. In addition, new C. americana germplasm was procured from across the native range of the species. The new collection of 1335 plants from 122 seed lots represents 72 counties and 22 states. The interspecific hybrid progenies and a subset of the American collection (616 trees from 62 seed lots) were field planted and evaluated for EFB response following field inoculations and natural disease spread over seven growing seasons. EFB was rated on a scale of 0 (no EFB) to 5 (all stems containing cankers). Results showed that progeny means of the interspecific hybrids ranged from 0.96 to 4.72. Fourteen of the 31 progenies were composed of at least one-third EFB-free or highly tolerant offspring (i.e., ratings 0–2), transmitting a significant level of resistance/tolerance. Several corresponding C. americana accessions that imparted a greater degree of resistance to their hybrid offspring were also identified. In addition, results showed that 587 (95.3%) of the 616 C. americana plants evaluated remained completely free of EFB. These findings confirm reports that the species rarely expresses signs or symptoms of the disease and should be robustly studied and exploited in breeding.

Development of interspecific hybrid progenies of mango and their characterization

A total 26 interspecific mango hybrids population were obtained from the crosses involving Alphonso, Amrapali and NR34 as a female parents and Mangifera odorata Griff, as male parent. Morphological traits revealed that all the interspecific hybrids as well as parent trees were found to be erect and also spreading habit with circular, semicircular and oblong crown shape. The results of cytological studies showed that interspecific hybrids were also possessed the same somatic chromosome number 2n = 40 as that of mango. Most of the interspecific hybrids showed the intermediate to dense foliage density. Out of 11 SSR markers, three primers showed high polymorphism and confirmed the hybridity based on the allelic range variation among the four parental mangoes.

Genome-wide identification of drought-responsive microRNAs in two sets of Malus from interspecific hybrid progenies

Drought stress can negatively impact apple fruit quality and yield. Apple microRNAs (miRNAs) participate in apple tree and fruit development, as well as in biotic stress tolerance; however, it is largely unknown whether these molecules are involved in the drought response. To identify drought-responsive miRNAs in Malus, we first examined the drought stress tolerance of ten F1 progenies of R3 (M. × domestica) × M. sieversii. We performed Illumina sequencing on pooled total RNA from both drought-tolerant and drought-sensitive plants. The sequencing results identified a total of 206 known miRNAs and 253 candidate novel miRNAs from drought-tolerant plants and drought-sensitive plants under control or drought conditions. We identified 67 miRNAs that were differentially expressed in drought-tolerant plants compared with drought-sensitive plants under drought conditions. Under drought stress, 61 and 35 miRNAs were differentially expressed in drought-tolerant and drought-sensitive plants, respectively. We determined the expression levels of seven out of eight miRNAs by stem-loop qPCR analysis. We also predicted the target genes of all differentially expressed miRNAs and identified the expression of some genes. Gene Ontology analyses indicated that the target genes were mainly involved in stimulus response and cellular and metabolic processes. Finally, we confirmed roles of two miRNAs in apple response to mannitol. Our results reveal candidate miRNAs and their associated mRNAs that could be targeted for improving drought tolerance in Malus species, thus providing a foundation for understanding the molecular networks involved in the response of apple trees to drought stress.

Inheritance of Marker Genes among Progeny of Interspecific Tomato Hybrids Expressing the recA Escherichia coli Gene

In interspecific hybrids a decrease in genetic exchanges between chromosomes from different species and negative interactions between functionally incompatible loci limit genetic variation among the progeny. Earlier the fraction of crossover genotypes was increased in intraspecific hybrids of the cultivated tomato Solanum lycopersicum with the expression of the recA Escherichia coli gene. In this research transgenic hybrids between S. lycopersicum and some wild tomato species were obtained in order to study the effect of recA gene expression on the frequency of crossovers in the progeny of interspecific hybrids. Interspecific hybrids showed negative interactions between the loci of the cultivated tomato and the S. cheesmaniae, S. pimpinellifolium, and S. habrochaites species. In the latter case it resulted in semilethal necrosis. The recA gene expression in interspecific hybrids with S. cheesmaniae partially compensates among the F2 progeny the deficiency of recessive genotypes at the Wv:wv locus of chromosome 2. In general, the fractions of crossover genotypes in the F2 progeny were higher in transgenic interspecific hybrids than in control non-transgenic hybrids of the same combination of crossing, but lower than in intraspecific S. lycopersicum hybrids.

Tolerance of novel inter-specific shrub willow hybrids to water stress

KEY MESSAGE: Novel interspecific hybrid progeny displayed hybrid vigor for some key biomass traits under well-watered and water-stressed conditions, but response was genotype-specific. Adaptation to stresses caused by climate change resulting from greenhouse gas emissions will become increasingly important for perennial crop breeding programs in the coming decades. Shrub willow (Salix spp.) is a strong candidate for short rotation coppice bioenergy production due to its high biomass production capacity, especially in temperate, northern latitudes. However, climate change is expected to increase temperature and the unpredictability of growing-season precipitation in these regions. Previous research has shown that interspecific breeding of shrub willow has resulted in hybrid vigor for biomass production. It is unclear how novel hybrids will perform in water limiting conditions. Using a biparental breeding scheme with common S. purpurea male or female parents, we tested parents and progeny for changes in growth and physiological traits under well-watered conditions and two levels of water stress. Water stress treatments caused reductions in above- and belowground biomass, leaf traits and stomatal conductance, mainly at the severe treatment level. At the genotypic level, hybrid progeny generally outperformed their parents for growth and biomass traits, demonstrating heterosis in these interspecific crosses. We found evidence that genotypes with the highest rates of biomass production are most severely impacted by water stress. Foliar SPAD measurements, a proxy for foliar N, were unaffected by water stress treatments. Biomass among genotypes in this controlled environment experiment was significantly correlated with field-grown plants, validating that these results can help to inform future breeding efforts targeting improved crop performance in drier growing environments.

ESA1 Is Involved in Embryo Sac Abortion in Interspecific Hybrid Progeny of Rice.

The emergence of sterile individuals in the hybrid backcross progeny of wild and cultivated rice limits the use of wild rice alleles for improving cultivated rice, but the molecular mechanisms underlying this sterility remain unclear. Here, we identified the semisterile introgression line YIL42, derived from a cross between the indica rice variety Teqing (Oryza sativa) and Oryza rufipogon accession YJCWR (Yuanjiang common wild rice), which exhibits semisterility. Using positional cloning, we isolated EMBRYO SAC ABORTION 1 (ESA1), which encodes a nuclear-membrane localized protein containing an armadillo repeat domain. A mutation in ESA1 at position 1819 (T1819C) converts a stop codon into an Arg (R) codon, causing delayed termination of protein translation. Analysis of transgenic lines indicated that the difference in ESA1 protein structure between O. rufipogon-derived ESA1 and Teqing-derived esa1 affects female gamete abortion during early mitosis. Fertility investigation and expression analysis indicated that the interaction between ESA1 T1819 and unknown gene(s) of Teqing affects spikelet fertility of the hybrid backcross progeny. The ESA1 T1819 allele is present in O. rufipogon but absent in O. sativa, suggesting that variation in ESA1 may be associated with interspecific hybrid incompatibility between wild and cultivated rice. Our findings provide insight into the molecular mechanism underlying female sterility, which is useful for improving the panicle seed setting rate of rice and for developing a strategy to overcome interspecific hybrid sterility between cultivated rice and wild rice.

Бульбоутворююча здатність потомства міжвидових та міжсортових гібридів картоплі

Бульбоутворююча здатність потомства міжвидових та міжсортових гібридів картоплі

Effects of symbiotic fungi on seed germination of interspecific hybrid progenies in Orchidaceae

Effects of symbiotic fungi on seed germination of interspecific hybrid progenies in Orchidaceae

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue.

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a very important disease of cauliflower (Brassica oleracea botrytis group) resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1) were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2n = 18, CC) × B. carinata (2n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.

Impacts of the dry season on the gas exchange of oil palm (Elaeis guineensis) and interspecific hybrid (Elaeis oleífera x Elaeis guineensis) progenies under field conditions in eastern Colombia

Elaeis guineensis palms and its interspecific hybrid (E. oleifera x E. guineensis) were planted in 2004 in the Cuernavaca farm of Unipalma S.A., located in the municipality of Paratebueno (Cundinamarca, Colombia). The palms were planted in two fields: Mecasaragua and Aurora. The first field has never been irrigated, and the second one (Aurora) has always been flood-irrigated during the dry season according to the parameters of the plantation. In this study, physiological parameters (gas exchange and water potential) were assessed in three seasons of the year 2013 (dry season, dry-to-wet transition season and wet season). Significant gas exchange differences were found among the seasons in the field with no irrigation (Mecasaragua). Likewise, differences between the genetic materials were observed during the dry season. For example, the photosyn thesis decreased by 75% compared with the palms planted in the irrigated field. No differences among seasons or materials were found in the irrigated field (Aurora). E. guineensis palms were more sensitive to water stress compared with the OxG interspecific hybrid. Both genetic materials responded rapidly to the first rains by leveling their photosynthetic rates and demonstrated an excellent capacity to recover from water stress.