Genetic evaluation of interspecific hybrids between a sexual synthetic autotetraploid P. plicatulum × P. aff. wrightii apomictic tetraploid, of the Plicatula group of Paspalum

Interspecific triploid hybrids were developed between tetraploid cultivated species Gossypium barbadense cv. Suvin and TCB 37 and diploid wild species Gossypium armourianum. The F1 hybridity was confirmed by morphological, cytological and molecular approaches. The ploidy level of interspecific F1 hybrid was triploid and completely male sterile. Female parents Suvin and TCB 37 had erect growth habit, yellow petals, palmate leaves, green stem, thick and prominent leaf veins, but Suvin had dense yellow anthers while TCB 37 was with dense creamy anthers whereas male parent has a spreading growth habit, yellow petals, cordate leaves, reddish green stem, medium dense yellow anthers, thin leaf veins, protruded stigma and glabrous plant body. The growth habit, petal colour, leaf shape and size of interspecific F1 hybrid were intermediate. Plant stem colour, hairyness, leaf pubescence and anther colour of Gossypium armourianum were observed to be dominant as hybrid fully resembled Gossypium armourianum for these characters. Petal spot was observed in both male and female parents but F1 hybrids had different intensity of petal spot in their petals. Variable expression of petal spot, anther colour and filament colour was observed in the F1 hybrids. Gossypium barbadense cv. Suvin and TCB 37 had 52 chromosomes, Gossypium armourianum had 26 chromosomes and the interspecific F1 was with 39 chromosomes. Significant differences were observed between pollen size, pollen fertility of parents and their hybrids. The F1 interspecific hybrid having more than 97% of sterile pollen grains. Out of 6 polymorphic SSR markers between parents, 3 markers unambiguously confirmed the hybrid status of interspecific hybrid. This hybrid may serve as useful genetic resource for the transfer of jassid resistance gene to Gossypium barbadense cultivars.

High quality forage production is needed in late summer and fall until frost. The pearl millet (Pennisetum americanum ✕ napiergrass (P. purpureum Schum.) interspecific hybrids have potential for producing high quality forage during this period but more than 1 year's data on a number of hybrids using different female parents is limited. In 1976, 1977, and 1978, 20 pearl millet ✕ napiergrass interspecific hybrids were seeded in the field in a Fuquay soil (Arenic Plinthic Paleudults : loamy, siliceous thermic) and evaluated for dry‐matter yield percent in vitro dry‐matter digestibility (IVDMD), percent crude protein, agronomic characteristics (seed Production, pest resistance, yield distribution), and breeding behavior (effects of male and female parents on dry matter yield). Most of the interspecific hybrids were equal to the best pearl millet hybrids in yield, IVDMD, and protein. In 1977 and 1978, six and two interspecific hybrids, respectively, were significantly (P = 0.05) higher in dry matter yield. One hybrid, Tift 23A ✕ N23, yielded 34 and 27% more dry matter in 1977 and 1978, respectively, than the best pearl millet hybrid. Hybrids with ‘Tift 23A1’ yielded over 25% more dry matter than hybrids with ‘Tift 23D2A1 when the same male parents were used on both female parents. One of the major advantages of the interspecific hybrids is that they produced almost 50% of their forage from after the middle of August until early December.This study also showed that of the three female parents tested, Tift 23A1 produced the highest yielding hybrids and that much variability for maximizing yield exists among the napiergrass clones used as male parents in the interspecific hybrids.

The seeds of plants are carriers of a variety of beneficial bacteria and pathogens. Using the non-culture methods of building 16S rDNA libraries, we investigated the endophytic bacterial communities of seeds of four hybrid maize offspring and their respective parents. The results of this study show that the hybrid offspring Yuyu 23, Zhengdan958, Jingdan 28 and Jingyu 11 had 3, 33, 38 and 2 OTUs of bacteria, respectively. The parents Ye 478, Chang 7-2, Zheng 58, Jing 24 and Jing 89 had 12, 36, 6, 12 and 2 OTUs, respectively. In the hybrid Yuyu 23, the dominant bacterium Pantoea (73.38%) was detected in its female parent Ye 478, and the second dominant bacterium of Sphingomonas (26.62%) was detected in both its female (Ye 478) and male (Chang 7-2) parent. In the hybrid Zhengdan 958, the first dominant bacterium Stenotrophomonas (41.67%) was detected in both the female (Zheng 58) and male (Chang 7-2) parent. The second dominant bacterium Acinetobacter (9.26%) was also the second dominant bacterium of its male parent. In the hybrid Jingdan 28, the second dominant bacterium Pseudomonas (12.78%) was also the second dominant bacterium of its female parent, and its third dominant bacterium Sphingomonas (9.90%) was the second dominant bacterium of its male parent and detected in its female parent. In the hybrid Jingyu 11, the first dominant bacterium Leclercia (73.85%) was the third dominant bacterium of its male parent, and the second dominant bacterium Enterobacter (26.15%) was detected in its male parent. As far as we know, this was the first research reported in China on the diversity of the endophytic bacterial communities of the seeds of various maize hybrids with different genotypes.

Evapotranspiration partitioning and variation of sap flow in female and male parents of maize for hybrid seed production in arid region

Developing partial interspecific hybrids of Momordica charantia × Momordica balsamina and their advance generations

Selection and characterization of an improved strain produced by inter-species hybridization between Pyropia sp. from India and Pyropia haitanensis from China

Key messageTetraploid `Moncada´ mandarin, used as male and female in interploidy hybridizations, displays mainly tetrasomic inheritance for most LGs, with slight variations according to the direction of the crossing.Triploid-breeding programs in citrus are key tool to develop seedless cultivars. Obtaining triploid citrus hybrids may be achieved through different strategies, such as the exploitation of female unreduced gamete in crosses between diploid parents and diploid by tetraploid sexual hybridizations, in which tetraploid genotypes can be used as male or female parents. Genetic configuration of triploid populations from interploid crosses greatly depends on the chromosomic segregation mode of the tetraploid parent used. Here, we have analyzed the inheritance of the tetraploid ‘Moncada’ mandarin and compared the genetic structures of the resulting gametes when used as male and as female parent. The preferential chromosome pairing rate is calculated from the parental heterozygosity restitution (PHR) of codominant molecular markers, indicating the proportion between disomic and tetrasomic segregation. Tetraploid ‘Moncada’ both as female and male parent largely exhibited tetrasomic segregation. However, as female parent, one linkage group (LG8) showed intermediate segregation with tendency towards tetrasomic inheritance, while another linkage group (LG4) evidenced a clear intermediate segregation. On the other hand, when used as male parent two linkage groups (LG5 and LG6) showed values that fit an intermediate inheritance model with tetrasomic tendency. Significant doubled reduction (DR) rates were observed in five linkage groups as female parent, and in six linkage groups as male parent. The new knowledge generated here will serve to define crossing strategies in citrus improvement programs to efficiently obtain new varieties of interest in the global fresh consumption market.

SummaryUsing an embryo rescue technique, we obtained an F1 plantlet whose female parent was a purple chilli pepper (Capsicum annuum 7033) and whose male parent was a green chilli pepper (C. chinense 7020).We verified the origin of this interspecific hybrid using a peroxidase isozyme assay and random amplified polymorphic DNA (RAPD) markers. Most of the morphological features of the F1 plant, particularly the purple colour of its foliage, flowers and immature fruit, were intermediate between those of its parents. Cytological analysis indicated that the meiotic chromosomes of the pollen mother cells of the F1 plant exhibited abnormal behaviour, resulting in a marked reduction in the proportion of fertile pollen compared to both its parents. Sequence analysis of the internal transcribed spacer of nuclear ribosomal DNA demonstrated that, compared to the parental sequences, the F1 hybrid had 186 polymorphic sites, 139 of which (74.7%) were inherited from the male parent, and 23 (12.4%) were inherited from the female parent, and 24 (12.9%) were transversions or base pair mutations. Therefore, our morphological and cytological observations, as well as isozyme and molecular marker analyses confirmed that the F1 plant was a genuine interspecific hybrid that had inherited more genetic information from its male parent than from its female parent. This work will help locate purple colour-related genes and the breeding of pepper cultivars containing higher concentrations of anthocyanin and capsaicin.

1. The artificial interspecific F1 hybrid between Papaver orientale L. (_??_) and P. somniferum L. (_??_) was produced in May, 1956. Its seeds were sown in October in the same year and 7 hybrids germinated the next month. Only one hybrid flowered in July, 1957.2. The somatic chromosome number in the hybrid was 32, the sum of the haploid numbers, 11 and 21, in the male and female parents, respectively.3. The hybrid was perennial like the female parent.4. The adult leaves of the hybrid were hispid on both sides and the petioles were canaliculate, like the female parent. It is very interesting, however, that the mode and extent of resemblance to the parents in the characters of leaves varied with stages of growth. During some months after germination, the hybrid was very similar to the female parent, but from early April, it began to resemble the male parent rather than the female parent. Finally, by late May, the hybrid was an intermediate between the two parents.5. The stems, peduncles, flower-buds, and floral leaves were all like those of the female parent. The made of ramification of the flowering shoot resembled that of the male parent.6. The presence of morphine, codeine, thebaine, and isothebaine in the hybrid was demonstrated by chemical separations and paper chromatography.7. Morphine and codeine in the hybrid are considered to have been inherited from the male parent and isothebaine from the female parent.8. Oripavine, an alkaloid characteristic of the female parent, was not proved in the hybrid.

Interspecific hybrid (F1) between spine gourd (Momordica dioica) and teasle gourd (Momordicasubangulata Blume subsp. Renigera (G. Don) WJJ de Wilde) produced through bagging and hand pollination showed vigorous growth habit with less fertility. Morphological parameters along with meiotic, mitotic chromosome behaviors and Randomly Amplified Polymorphic DNA (RAPD) analysis, confirmed interchanges of genetic characters in the new hybrids. The interspecific hybrid showed a vigorous foliage with intermediate flower characters than that of parental species. Self pollination and backcrossing of F1plants to either parent confirmed presence of both male and female sterility, that might be due to improper meiotic chromosome pairing. The characters like petal spot and time of anthesis (early morning) were similar to that of pollen parent while the diameter and size of leaves and flowers, pedicel length and plant growth were intermediate as compared to parents. Somatic chromosome analysis revealed 2n = 28 in M.dioica – the female parent, 2n = 56 in M. subangulata ssp. renigera - the male parent and 2n = 42 in F1hybrid of M. dioica × M. subangulata ssp. renigera. RAPD analysis of both the parents and F1 hybrid confirmed more genetic affinity (60.95%) with female parent than the male parent (32.35%). Primer specific DNA markers confirmed the introgression of male genetic elements into the newly developed amphidiploids. Incorporation of male specific DNA markers into the F1 hybrid is discussed. Preliminary evaluation indicates that the F1 plants sprouted early, which is lacking in the mother parent and this character could be exploited by restoring of fertility by chromosome doubling. Key words: Momordica, cytomorphology, F1 hybrid, karyotype, RAPD markers.

Hybridization is the main method for obtaining genetic diversity and breeding new varieties of tea. The purpose of this research is to determine the morphological potential of each progeny from crossing between male and female parents which can then be used as a source of information in developing high quality superior tea clones through tea breeding activities. Male and female parents with the desired traits were crossed to form genetic diversity. 34 progenies resulted from crosses formed from crossing 4 male parents and 3 female parents. All parents and progeny were characterized morphologically and yield components. Data on morphological characters and yield components were analyzed descriptively. Correlation analysis and Principles Component Analysis Biplot (PCA Biplot) were also performed using R software. Male tea parents and female tea parents are in different groups based on morphological characteristics. Progeny-17, Progeny-18, Progeny-4, Progeny-5, and Progeny-27 had a higher total number of shoot and potential yield per bush compared to the other progenies.

The field experiment was carried out during Kharif 2016 at the Main Agricultural Research Station, to investigate the effect of staggered sowings and application of additional dose of nitrogen to late parent on synchronization of male and female parents of pearl millet hybrid BPMH-3. The field experiment comprised of twelve treatments with three replications in split plot design. The results revealed that staggered sowing of male parent nine days earlier than female (S4) took less number of days for panicle initiation, flower initiation and 50 per cent flowering in male. On the other hand simultaneous sowing of female and male parent (S1) recorded the lowest values for growth parameters and it took more number of days to panicle initiation, flower initiation and 50 per cent flowering. This revealed that sowing of male parent nine days earlier than the female parent and application of additional 10 kg N ha-1 to male parent at 35 days after sowing (S4) was appropriate to achieve nicking between female and male parental lines of pearl millet hybrid, BPMH-3. Another experiment was conducted at Saidapur farm, University of Agricultural Sciences, Dharwad, to study the flowering behaviour of TPRT 111 (male) and ICMA 9277 (female) parents of pearl millet BPMH-3 in periodical date of sowing with fifteen days interval from first June, 2016 to Second fortnight of December, 2016. The results revealed that the female (ICMA 9277) and male (TPRT 111) parental lines took significantly more number of days 52.00 days and 64.00 days respectively when sown during first fortnight of June 2016. While, less number of days was recorded by female and male parental lines (46.00 days and 51.00 days respectively) when sown during second fortnight of December 2016. Progressive decline in days to fifty percent flowering was observed with the advancement in the sowing which narrow down the flowering gap between male and female parental line.

Interspecific hybrids between pearl millet (Pennisetum glaucum) and napier grass (Pennisetum purpureum) give rise to perennial fodder crops characterized by high biomass, broad clumps and good palatability. These hybrids are triploid and developed by hand pollination of napier grass pollen on pearl millet panicles. The progeny shows a high percentage of pearl millet genotype due to self-pollination in the female parent. Identification of hybrids at a young stage based on morphological characters is difficult. DNA-based molecular markers have high discriminating power and were used to assess genetic differences between hybrids and their parents. Genetic diversity was studied in 18 pearl millet × napier grass hybrids along with their parents and two released national checks using inter simple sequence repeat (ISSR) markers. Eight ISSR primers gave rise to 125 bands, of which 120 bands were polymorphic. Polymorphic information content and ISSR primer index ranged from 0.40 to 0.49 and 8.88 to 11.14, respectively. The hybrids showed the presence of unique bands, besides those shared with male and female parents. Female (pearl millet) parents formed a separate group in the dendrogram constructed based on ISSR polymorphism. The male (napier grass) parents formed a separate group along with hybrids, indicating a higher similarity of hybrids with the male parents. Principal component analysis and STRUCTURE analyses showed a similar grouping. The close resemblance of hybrids to the male parents confirmed their interspecific origin. The study revealed that ISSR marker analysis could be a quick and reliable method to identify interspecific hybrids at an early stage of growth.

In order to investigate the possible relation between meiotic time and meiotic chromosome pairing behaviour, meiosis was timed in various forms of wheat and wheat hybrids. First, meiosis was timed in tenTriticum aestivum(var. Chinese Spring) genotypes with different chromosome constitutions which differed widely in the meiotic pairing behaviour. Secondly, in order to escape from the disadvantage of aneuploid material, meiosis was also timed in plants which differed in the extent of homoeologous pairing because of the activities of different alleles at one or two loci. For this experiment use was made of F1-hybrids from the crossT. aestivumxAegilops muticawhich, although they all have 28 chromosomes, differ widely in the amount of homoeologous pairing. Thirdly, meiosis was also timed in 28-chromosome and 29-chromosome plants derived from the cross between rye(Secale cereale)x 43-chromosomeT. aestivumcontaining a singleAe. muticaaddition chromosome known to carry genes which greatly affect the level of homoeologous pairing in wheat. Although the 28-chromosome plants display very little pairing (chiasma frequency per cell (c. f.) = 0.5) while 29-chromosome plants display a much higher amount of pairing (c. f. = 7.8) no difference in meiotic time was detected between them. Similarly, the duration of meiosis was not significantly different between the three types of F1-hybrids betweenT. aestivumxAe. muticawhich had chiasma frequencies of 14.3, 7.4 and 0.9. Thus, these results agree in showing that there was no correlation between the duration of meiosis and the amount of homoeologous chromosome pairing. The results obtained for genotypes of Chinese Spring also provided no evidence to support the notion that there is a relation between the level of chromosome pairing and the duration of the pairing process. Consequently some doubt must be cast upon the idea that the time available for pairing is limiting to the pairing process. It was shown that individual wheat chromosomes in Chinese Spring differed in their effects on meiotic duration. For instance, the absence of chromosome 7B has no detectable effect on meiotic duration. The absence of chromosome 5B in two genotypes resulted in an increase in meiotic time from that found in euploid plants (24 h) to that found in tetraploid wheat species (about 30 h). By using plants ditelosomic for chromosome 5BLit was shown that most, if not all, of the genetic effects of chromosome 5B on meiotic time are determined by the short arm.

An interspecific hybridization program designed to transfer gene(s) controlling apomixis from Pennisetum squamulatum Fresen. (2n=6x=54) to induced tetraploid (2n=4x=28) cultivated pearl millet, Pennisetum americanum (L.) Leeke resulted in four offtype plants, two with 27 chromosomes and two with 28 chromosomes. These plants were found among 217 spaced plants established from open-pollinated seed of an apomictic 21-chromosome polyhaploid (2n=21) plant derived from an apomictic interspecific hybrid (2n=41) between tetraploid pearl millet and Pennisetum squamulatum. It appeared that a 21- (or 20-) chromosome unreduced egg from the apomictic polyhaploid united with a 7-chromosome pearl millet (2n=2x=14) gamete to produce a 28- (or 27-) chromosome offspring. Meiotic chromosome behavior was irregular averaging from 3.60 to 4.05 bivalents per microsporocyte in the 27- and 28-chromosome hybrids. The 27- or 28-chromosome hybrids, like the 21-chromosome female parent, shed no pollen, but set from 1.8 to 28 seed per panicle when allowed to outcross with pearl millet. Progeny of the 28-chromosome hybrids were uniform and identical to their respective female parents, indicating that apomixis had been effectively transferred through the egg. In addition, a 56-chromosome plant resulting from chromosome doubling of a 28-chromosome hybrid was identified. Pollen was 68 per cent stainable and the plant averaged 2.3 selfed seeds per panicle. Chromosomes of the 56-chromosome plant paired as bivalents (x=10.67) or associated in multivalents. Three to nine chromosomes remained unpaired at metaphase I. Multiple four-nucleate embryo sacs indicated the 56-chromosome hybrid was an obligate apomict. The production of 27-, 28-, and 56-chromosome hybrid derivatives were the results of interspecific hybridization, haploidization, fertilization of unreduced apomictic eggs, and spontaneous chromosome doubling. These mechanisms resulted in new unique genome combinations between x=7 and x=9 Pennisetum species.