Source Of Male Sterility Research Articles

Identification of stable restorers and high-yielding hybrids using diverse sorghum male sterile cytoplasmic sources and established pollen parents under different water regimes

Identification of stable restorers and high-yielding hybrids using diverse sorghum male sterile cytoplasmic sources and established pollen parents under different water regimes

Understanding the number of genes governing fertility restoration and isolation of potential restorers on maldandi source of male sterility in rabi sorghum [Sorghum bicolor (L.) Moench

DSMR-4 and DSMR-8, two promising restores, were crossed with M 31-2A maldandi cytoplasm. The obtained hybrids were assessed in three sets of tests, F2: BC1F1, F2: F3, and F4 kharif: F4 rabi generation, in order to determine the number of genes driving the segregating pattern. Three genes are involved in the initial set of segregation patterns for both crosses: in the F2 generation, there were 54 fertile: 10 sterile and in the BC1F1 generation, there was 1 fertile: 1 sterile. Two of these genes are required for the restoration and function in a duplicate complimentary manner. Further, both the crosses were grown in F3 generation to confirm the stability of restorers. They were segregated in the ratio of 10 true-breeding families and 44 segregating families, which confirmed F2 ratio. Further, only true breeding 49 to 54 families of both the crosses were forwarded to F4 generation and evaluated in both kharif and rabi seasons. In both seasons, they segregated in the ratio of 4 true-breeding families and 6 segregating families. The current study revealed the reliability of gene action for fertility restoration increased from F2 to F4 because of the fixation of alleles.

A Single Nucleotide Polymorphism Unique to the Galanthum-CMS of Onion

Different sources of cytoplasmic male sterility (CMS) are used to produce hybrid onion seed. The most commonly used source of CMS in onion is S cytoplasm (S-CMS), and male fertility is restored by a dominant allele at the nuclear male-fertility restoration locus (Ms). Male-sterile plants possess S cytoplasm and have the homozygous recessive genotype at Ms; seed propagation of male-sterile plants is possible by crossing with a male-fertile maintainer plant or inbred possessing normal (N) male-fertile cytoplasm and the homozygous recessive at the Ms locus (N msms). Some commercially important onion populations possess S-CMS and high frequencies of the dominant Ms allele, eliminating the possibility to develop maintainer lines. An alloplasmic source of CMS (Gal-CMS) was developed by backcrossing the cytoplasm of Allium galanthum into the nuclear background of onion. The advantage of Gal-CMS is that the dominant allele at Ms does not restore male fertility, making this source of CMS useful for the development of male-sterile lines from populations possessing S cytoplasm and dominant allele(s) at Ms. In this research, a single nucleotide polymorphism unique to the cytoplasms of A. galanthum and Gal-CMS was identified, useful to distinguish Gal-CMS from other onion cytoplasms.

Floral morphology of 'Anand' rapid cycling Brassica oleracea .

Abstract The 'Anand' type of cytoplasmic male sterility (CMS) was introduced to Brassica oleracea through protoplast fusion (Cardi and Earle, 1997), providing a source of male sterility that is of value in producing F1 hybrid varieties of this species without the cold sensitivity of 'Ogura' cytoplasm. In this species, as in others in which it has been introduced, 'Anand' mitochondria are associated with flower abnormalities. The best lines have been used by commercial breeders. This paper describes 'Anand' flower abnormalities in further detail. Rapid cycling brassica with 'Anand' cytoplasm may have promise as a model system for research on floral patterning. Materials and Methods. Three lines of rapid cycling B. oleracea carrying the 'Anand' cytoplasm and one wild type were grown. The flower morphology of 'Anand' lines was classified as good in F25-F-1A, fair in F25-F-6B, and poor in F23-F-1B (Cardi and Earle, 1997). Seedlings were started in an indoor growth room, but were maintained in a naturally lit greenhouse at 20° night, 25° day during flowering. Five flowers on 5 plants of each line were examined. Results. Morphological abnormalities affected all floral parts (Table 1). There was substantial variation among flowers on individual plants and among lines but little within lines. Conclusions. "Good" flowers have large petals that push open the sepals before the carpel elongates. Female fertility could be reduced due to occlusion of the stigma or physical damage caused by the stigma pressing against the end of a sepal and kinking the style. Female fertility in some flowers was unlikely because the carpel suture failed to fuse. In some cases the edge of the split carpel was sepal-like, consistent with the absence of SEPALLATA expression. The stigma on a sepal represents the converse. Stamens were most strongly affected, with outer stamens most reduced. This whorl is the one most frequently suppressed in flowering plants (Masters, 1869). The number of stamens was reduced to varying degrees. First to be lost was one or both of the pair outside the petals. Then the outer pair inside the petals was affected. One or both of these stamens could either be lost or doubled to give 3 to 5 stamens. Again a positional cue for stamens appears to be weakened. Anther development was often limited, the expected and desired consequence of the Anand genotype. Some undehisced " good " anthers contained pollen. There is variation even among the lines initially described as " good ". Further selection among these may help identify those that are most promising for further use in hybrid production.

Identification of sources of male sterility in the Colombian Coffee Collection for the genetic improvement of Coffea arabica L.

In coffee (Coffea arabica L.), male sterility is a prerequisite for the exploitation of heterosis since it provides an efficient and reliable method for the production of hybrid seeds. Given its relevance, the objective of this study was to identify male-sterile genotypes within the Colombian Coffee Collection that can be used in genetic improvement. For this purpose, Ethiopian germplasm and progenies derived from hybrids between C. arabica x C. canephora were explored between 2017 and 2021. In the first stage, genotypes without visual presence of pollen were preselected in the field, followed by selection through staining and verification of male sterility and female fertility through directed crosses (directed, reciprocal and selfing). In this stage, 9,753 trees were explored, preselecting 2.4% due to visual absence of pollen. The staining of structures allowed us to confirm the lack or sporadic production of pollen in 23 individuals of Ethiopian origin. The results of the directed crosses led to the identification of 11 male-sterile and 12 partially male-sterile genotypes belonging to 15 accessions. In all cases, the individuals were characterized by the presence of anthers but with an absence or low content of pollen, which is why the male sterility is possibly of the sporogenic type. The female receptivity values were between 2.9% and 72.6%, being higher than 30% in five genotypes. These genotypes are a valuable tool for the genetic improvement of C. arabica with the potential to facilitate the use of heterosis and to allow a deeper understanding the development of male gametophytes in the species.

Development of new sources of male sterility in sunflower (Helianthus annuus L.) : Limitations and opportunities

Cytopasmic male sterility (CMS) is a reasonably common characteristic of higher plants. The discovery of astable source of CMS was the first step towards the practical use of heterosis in sunflower. The second step was the discovery of fertility restoration gene(s). The first CMS (CMS89) in sunflower was reported in descendants of an interspecific hybrid between Helianthus petiolaris Nutt. and cultivated sunflower (the variety Armavirskiy-9345). Although CMS89 or its derivatives are used to produce all commercial sunflower hybrids, more than 72 additional sources ofsunflower CMS have been described by variousscientists. Male sterility may have multiple causes. It can result from adverse growth conditions, from diseases, or from mutations. In this paper, CMS sources obtained by different methods like hybridization (both intraspecific and interspecific crosses), mutagenesis, chemical and spontaneous occurrence of male sterility as well as limitations and opportunities of diverse CMS sources in sunflower were discussed.

Development of mitochondrial simple sequence repeat markers to simultaneously distinguish cytoplasmic male sterile sources in cotton.

Deleterious effects on anther development andmain economy traits caused by sterile genes or cytoplasms are one of the important genetic characteristics of cytoplasmic male sterility (CMS) systems in cotton, which severely hinder the large-scale application of "three-line" hybrids in production. Therefore, distinct characterization of each cytoplasmic type is mandatory to improve the breeding efficiency of cotton hybrids. In this study, four isonuclear-alloplasmic cotton male sterile lines withG. hirsutum (CMS-(AD)1), G. barbadense (CMS-(AD)2), G. harknessii (CMS-D2), and G. trilobum (CMS-D8) cytoplasms were first created by multiple backcrosses with common genotype Shikang126. Then, 64 pairs of mitochondrial simple sequence repeat (mtSSR) markers were designed to explore the mitochondrial DNA diversities among four isonuclear-alloplasmic cotton male sterile lines, and a total of nine pairs of polymorphic mtSSR molecular markers were successfully developed. Polymorphism analysis indicated that mtSSR59 marker correlated to the atp1 gene could effectively divide the CMS-D2, CMS-(AD)1, and CMS-(AD)2 in one category while the CMS-D8 in another category. Further cytological observation and determination of ATP contents also confirmed the accurate classification of CMS-D2 and CMS-D8 lines. Moreover, the mtSSR59 marker was successfully applied in the marker-assisted selection (MAS) for breeding new male sterile lines and precise differentiation or purity identification of different CMS-based "three-line" and conventional cotton hybrids. This study provides new technical measures for classifying various cytoplasmic sterile lines, and our results will significantly improve the efficiency of there-line hybrid breeding in cotton.

Seed productivity of alloplasmic lines of Beta patula and B. maritima with sterile cytoplasm under the conditions of apozygotic reproduction

Purpose. Revealing the effect of the cytoplasmic genome of replaced lines with the plasma of wild species Beta patula and B. maritima L., and apozygotic lines A4–A8 with the cytoplasm of S vulgaris Owen on the main factors of apozygotic reproduction, seed productivity, germination, monogermity and sterility as affected by the genetic origin of breeding material.
 Methods. The research was carried out in the Cytogenetics Laboratory (IBCSB), the Laboratory for Apomixis and Polyploidy of the Yaltushkiv EBS, and the Laboratory for Adaptive Breeding (Veselyi Podil EBS). Apozygotic seeds were obtained under a pollen-free regime according to the IBCSB’s Methods for Spatial Isolation and Parchment Insulators. Each seed bearer plant phenotype was determined during the flowering period by pollen sterility and partial flowering. Classification of plants was performed according to Owen (1945), with identifying plants of CMS-0, Type CMS-1, and CMS-2 types. The Monogermity of seed plants was assessed visually by the presence of separate fruits on the central shoots. In 2021, the roots of the replaced lines of the Veselyi Podil EBS were planted under the conditions of a pollen-free regime in the experimental field of the IBCSB. Seed production under apozygositic conditions was studied, taking into account the number of set fruits per 10-cm segment with 5 replications for each seed bearer. Germination was determined on the 10th day and germination vigour on the 5th day.
 Results. New sources of cytoplasmic male sterility (CMS) were obtained in the cytogenetics laboratory based on a genetic model of crossbreeding analysis, using differentiation and tools according to the marker-linked genes of hypocotyl color R+r-, and one / two-year development cycle B+b-. The analyzers for the nature of sugar beet sterility were sterility maintainers, dominant homozygotes for recessive genes of anthocyanin color, development cycle, partial fertility and sterility (NBeta vulgaris Sxxzz rr bb). Monogerm pollen-sterile lines with an apomictic way of seed reproduction (Yaltushkiv EBS) (A4–A8 Beta vulgaris Sxxzz rr), selected for the dominant color of the hypocotyl R+r-, stabilized for the trait of monogermity, 100% sterility and 2x gene ploidy, were characterized by low seed productivity. High rates of apozygotic seed development (80 to 96.4% of the number of set flowers) were observed against the background of the sterile cytoplasm of Beta maritima (Turkey). In the CMS BC4S patula line, the number of set apozygotic seeds ranges from 34 ± 0.3 to 39 ± 0.42, and the indicators of degenerated flowers under apozygotic regime varied from 31.2 to 54.3%. Isolated were seed plants with high self-reproduction, such as BC4S maritima Turkey, k.2/1, k.6/2, k.6/3 and k.3/4, k.9/4 on the background of new plasma of wild species of B. patula. The phenomenon of high self-reproduction of seeds (up to 98.5−96.4% of set flowers) was detected in line 21-011 CHS BC5S patula, which was comparable with hybrids and sterility maintainers (97.5−93.1%), which is determined by a special interaction of the beet nuclear genome of sugar beet and new plasma of wild species of the genus Beta L.
 Conclusions. The apomictic way of seed reproduction ensures the shortening of the breeding scheme for sugar beet due to high seed reproduction of mother parent in substituted lines with new plasma and differentiation by gametophytic reduction of parthenogenesis using morphological marker traits.

Biodiversity of interspecific hybrids of the genus <i>Allium</i> L.

Relevance. Interspecific hybridization in the genus Allium L. is the best way to increase biodiversity by introgression of desired traits within the genus. This is valuable for signs such as resistance to diseases and pests, accumulation of important metabolites, obtaining new sources of cytoplasmic male sterility. The creation based on interspecific hybridization of fundamentally new plant forms with unique genetic material makes it possible to expand the selection of genotypes that are valuable in practical terms.Methods. To characterize the breeding material, the plants of interspecific allium hybrids were evaluated using morphological and phytopathological analyses. The analysis of plants of interspecific hybrids of the genus Allium L. from various inbred offspring from BC1-2 combinations of crossing species A. cepa × A. vavilovii and A. cepa × A. fistulosum by breeding characteristics was carried out. Plants were studied by weight, color, bulb shape, number, height of seed stalks, seed productivity and resistance to downy mildew.Results. The biodiversity of plants was revealed: by weight, shape, color of the bulb; by resistance to downy mildew of plants of the first year of vegetation and seed plants; by the number, height of seed stalk; by seed productivity. Plants of interspecific allium hybrids formed bulbs weighing up to 120 g, white, yellow, brown and red, elliptical, broadly elliptical, round and transversely elliptical bulb shape. Phytopathological assessment of allium plants of the first year of vegetation and seed plants revealed diversity in inbred offspring with resistance to peronosporosis. In the combination of crossing species A. cepa × A. vavilovii plants of the first year of vegetation had the largest number of resistant plants to downy mildew (up to 66.7%). According to the seed productivity of plants, depending on the combination of crossing, inbreeding generation and backcross, highly fertile plants with increased seed setability (up to 2.0 g /plant) were identified. The conducted studies have demonstrated an increase in the biodiversity of allium plants obtained based on interspecific hybridization, backcrosses and inbreeding.

Characterization, inheritance of male sterility and development of male sterile and maintainer lines in ridge gourd (Luffa acutangula (Roxb.) L.)

Two male sterile mutants IIHRRG-12MS (long fruited) and IIHRRG-28MS (medium long fruited) were identified from the ridge gourd germplasm IIHR-12 and IIHR-28 respectively at ICAR-IIHR, Bengaluru. These two male-sterile (ms) sources were characterized by the production of rudimentary male flowers in the racemes in contrast to the bright yellow flowers with fertile pollen and healthy anthers in male fertile, monoecious plants. Using these ms lines the inheritance of male sterility was worked out, which is cytoplasmic genic male sterility (CGMS) type, with single dominant gene either in homozygous or heterozygous condition restoring male fertility in the presence of sterile cytoplasm. In order to develop F1 hybrids using male sterility, several male sterile and maintainer lines were developed in different genetic back grounds such as green/dark green fruit colour and short/medium long/long fruit length.

Utilization of wild species for diversifying the cytoplasmic male sterility source of sunflower (Helianthus annuus L.) hybrids

Abstract The present investigation is directed at improving sunflower using hybrids having diverse cytoplasmic male sterile (CMS) sources from Helianthus annuus and H. argophyllus. The aim is to develop and identify promising lines and hybrids with a high combining ability and to obtain highly productive oilseed sunflower hybrids having diverse CMS sources. Five diversified CMS lines and 10 testers were crossed in a line × tester mating design to develop 50 F1 hybrids for genetic analysis. The pooled analysis of variance revealed significant differences among hybrids for the traits studied. The mean squares of lines and testers from crosses and GCA variance components revealed the prevalence of additive variances and additive gene action. The mean squares of lines × tester interactions were also significant for all the traits considered. The significance of lines × tester interactions and SCA variance components indicated that SCA is also important in the expression of traits and demonstrated the role of dominant and epistatic genes in controlling the various traits. Among the diverse CMS lines, ARG-6-3-1-4was identified as the best general combiner for stem diameter, volume weight, seed yield, hull content and oil content. While, the line ARG-2-1-2 was the best general combiner for days to 50 per cent flowering, head diameter, 100 seed weight and seed filling per cent. The tester M17-R was observed to be the best general combiner for earliness and volume weight, while RHA 93 was the best general combiner for plant height, seed yield and oil content. The crossMUT-2-8-3-2 × GKVK 3 was found to be a good specific combiner for stem diameter, 100 seed weight, seed yield, seed filling percentage and oil content while, ARG-6-3-1-4 × GKVK 3 was a good specific combiner for days to 50% flowering, plant height and 100 seed weight. The highest standard heterosis for seed yield was observed in the hybrid MUT-2-8-3-2 × GKVK 3 followed by ARG-2-1-2 × LTRR 822 while for oil content the highest was seen in the cross ARG-6-3-1-4 × RHA95-C-1 and thus these hybrids can be exploited for sunflower improvement and diversifying the cytoplasmic male sterile sources of this valuable oilseed crop.

Restoration ability of newly developed restorer gene pool inbreds on two different CMS sources in sunflower (Helianthus annuus L.)

Classical cytoplasmic male sterility (PET-1) discovered by Leclercq and a few restorer lines are being utilized for commercial hybrid seed production in sunflowers over the world since 1972. The utilisation of a single source of male sterility results in a high level of vulnerability to biotic and abiotic stresses. The goal of this study was to identify new fertility restorers for two different cytoplasmic male sterile sources, i.e., PET-1 (COSF-6A, COSF-7A, CMS-38A, ARM-248A) and CMS PEF (FMS-852A). Five CMS lines were crossed with newly developed drought tolerant 10 inbred lines in Line x Tester fashion and an evaluation of test cross progenies was conducted. All the inbreds were categorized into complete, partial restorers and maintainers through cytological observation. Six inbreds, viz., RGP-157, RGP-184, RGP-190, RGP-223, RGP-225 and RGP-233 behaved as restorers for all the CMS lines and restored fertility, while RGP-222 and 298R inbreds maintained sterility. The CMS line, FMS-852A was maintained by four inbreds indicating the involvement of different gene(s), while six inbreds, RGP-157, RGP-184, RGP-190, RGP-223, RGP-225 and RGP-233 were restored its fertility. None of the inbreds behaved as partial restorers for any of the CMS lines. The fertility restoration ranged from 91.4 to 97.4 per cent in different cross combinations. In the present study, pollen fertility of up to 80 per cent was observed for the PET-1 source. However, only 60 per cent of the pollen fertility was observed for CMS fallax. From the study, it was evident that among the two CMS sources, restorers for PET-1 and PEF were available. Efforts should be made to utilize CMS PEF for the production of more productive sunflower hybrids resistant to biotic and abiotic stresses. Keywords: CMS sources, Inbreds, Maintainer, Restorer, Sunflower

Comparative analysis of restoration behavior of milo (104A, 401A) and maldandi (M31-2A) based male sterile lines in sorghum [Sorghum bicolor (L.) Moench

In sorghum, milo source of male sterility has been used for developing all the hybrids so far and it created the narrow cytoplasmic base. In addition, it also narrows down the nuclear diversity which may be the invitation for the outbreak of pests and diseases in the near future. To handle this hazard new diverse sources like A2, A3, A4, maldandi, VZM and G1 have been discovered. The availability of restorers on these sources is very difficult hence their utilization is also a challenging task. The present study was, therefore, carried out to test different sorghum lines for restoration behavior on two milo lines (104A and 401A) and one maldandi (M31-2A) with more emphasis on maldnadi source because of its added advantage of enhancing grain size and pest tolerance. In rabi-2017, 125 genotypes were tested for the restoration behavior on these sources, and five restorers viz., IS 19389, IS 995, IS 28389, IS 26046 (BRJ 67-8) and DSMR-8 restored fertility on 104A, two lines viz., IS 29335 and IS 26046 restored on 401A, while on M31-2A six lines viz., IS 19975, BRJ-67-4 (DSMR-4), BRJ 67-8 (DSMR-8), BRJ 67-16, BRJ 67-19, BRJ 67-21 restored the fertility. only two lines DSMR-8 and DSMR-4 exhibited stable, consistent and strong restoration (> 90% seed set) across the seasons (rabi-2017 and kharif-2017) and years (2017 and rabi-2018). All the used MS lines exhibited the restoration complexity in the following order—104A < 401A < M31-2A.

The Gossypium anomalum genome as a resource for cotton improvement and evolutionary analysis of hybrid incompatibility.

Cotton is an important crop that has been the beneficiary of multiple genome sequencing efforts, including diverse representatives of wild species for germplasm development. Gossypium anomalum is a wild African diploid species that harbors stress-resistance and fiber-related traits with potential application to modern breeding efforts. In addition, this species is a natural source of cytoplasmic male sterility and a resource for understanding hybrid lethality in the genus. Here, we report a high-quality de novo genome assembly for G. anomalum and characterize this genome relative to existing genome sequences in cotton. In addition, we use the synthetic allopolyploids 2(A2D1) and 2(A2D3) to discover regions in the G. anomalum genome potentially involved in hybrid lethality, a possibility enabled by introgression of regions homologous to the D3 (Gossypium davidsonii) lethality loci into the synthetic 2(A2D3) allopolyploid.

Role of MS1 homolog Ntms1 gene of tobacco infertility.

The sterile line is the basis of crop heterosis utilization. To broaden the sources of male sterility in tobacco, the Ntms1 (Nicotiana tabacum L. ms1) gene was cloned from the tobacco variety K326 by homologous cloning based on the Cams1 (Capsicum annuum L. ms1) gene sequence of male-sterility genes in pepper. The protein structure and physicochemical properties of the two genes were determined by bioinformatics analysis, and the function of the Ntms1 gene was verified by the CRISPR/Cas9 system. The results showed that the sequences of Ntms1 and Cams1 were 85.25% similar, and plant homeodomains were found in both genes; the physical and chemical properties were also very similar. It is speculated that the Ntms1 gene had the same function as the Cams1 gene in controlling male sterility. Compared to the wild-type plants, the filaments of the Ntms1 knockout mutant plants were shorter, and the stamen was shorter than the pistil. The anthers did not develop fully and had few viable pollen grains; the tapetum and the anther wall had developed abnormally, and the anther chamber was severely squeezed. The malondialdehyde content in the mutant plants was significantly higher than that in the wild-type plants, while self-fertility was significantly lower in the mutant plants. The results showed that the Ntms1 gene plays an important role in regulating fertility in tobacco.

Elucidating Mitochondrial DNA Markers of Ogura-Based CMS Lines in Indian Cauliflowers (Brassica oleracea var. botrytis L.) and Their Floral Abnormalities Due to Diversity in Cytonuclear Interactions.

Mitochondrial markers can be used to differentiate diverse mitotypes as well as cytoplasms in angiosperms. In cauliflower, cultivation of hybrids is pivotal in remunerative agriculture and cytoplasmic male sterile lines constitute an important component of the hybrid breeding. In diversifying the source of male sterility, it is essential to appropriately differentiate among the available male sterile cytoplasms in cauliflower. PCR polymorphism at the key mitochondrial genes associated with male sterility will be instrumental in analyzing, molecular characterization, and development of mitotype-specific markers for differentiation of different cytoplasmic sources. Presence of auto- and alloplasmic cytonuclear combinations result in complex floral abnormalities. In this context, the present investigation highlighted the utility of organelle genome-based markers in distinguishing cytoplasm types in Indian cauliflowers and unveils the epistatic effects of the cytonuclear interactions influencing floral phenotypes. In PCR-based analysis using a set of primers targeted to orf-138, 76 Indian cauliflower lines depicted the presence of Ogura cytoplasm albeit the amplicons generated exhibited polymorphism within the ofr-138 sequence. The polymorphic fragments were found to be spanning over 200–280 bp and 410–470 bp genomic regions of BnTR4 and orf125, respectively. Sequence analysis revealed that such cytoplasmic genetic variations could be attributed to single nucleotide polymorphisms and insertion or deletions of 31/51 nucleotides. The cytoplasmic effects on varying nuclear-genetic backgrounds rendered an array of floral abnormalities like reduction in flower size, fused flowers, splitted style with the exposed ovule, absence of nonfunctional stamens, and petaloid stamens. These floral malformations caused dysplasia of flower structure affecting female fertility with inefficient nectar production. The finding provides an important reference to ameliorate understanding of mechanism of cytonuclear interactions in floral organ development in Brassicas. The study paves the way for unraveling developmental biology of CMS phenotypes in eukaryotic organisms and intergenomic conflict in plant speciation.

Genome-wide comparative transcriptome analysis of the A4-CMS line ICPA 2043 and its maintainer ICPB 2043 during the floral bud development of pigeonpea.

Cytoplasmic male sterility (CMS) offers a unique system to understand cytoplasmic nuclear crosstalk, and is also employed for exploitation of hybrid vigor in various crops. Pigeonpea A4-CMS, a predominant source of male sterility, is being used for efficient hybrid seed production. The molecular mechanisms of CMS trait remain poorly studied in pigeonpea. We performed genome-wide transcriptome profiling of A4-CMS line ICPA 2043 and its isogenic maintainer ICPB 2043 at two different stages of floral bud development (stage S1 and stage S2). Consistent with the evidences from some other crops, we also observed significant difference in the expression levels of genes in the later stage, i.e., stage S2. Differential expression was observed for 143 and 55 genes within the two stages of ICPA 2043 and ICPB 2043, respectively. We obtained only 10 differentially expressed genes (DEGs) between the stage S1 of the two genotypes, whereas expression change was significant for 582 genes in the case of stage S2. The qRT-PCR assay of randomly selected six genes supported the differential expression of genes between ICPA 2043 and ICPB 2043. Further, GO and KEGG pathway mapping suggested a possible compromise in key bioprocesses during flower and pollen development. Besides providing novel insights into the functional genomics of CMS trait, our results were in strong agreement with the gene expression atlas of pigeonpea that implicated various candidate genes like sucrose-proton symporter 2 and an uncharacterized protein along with pectate lyase, pectinesterase inhibitors, L-ascorbate oxidase homolog, ATPase, β-galactosidase, polygalacturonase, and aldose 1-epimerase for pollen development of pigeonpea. The dataset presented here provides a rich genomic resource to improve understanding of CMS trait and its deployment in heterosis breeding in pigeonpea.

A Study on Sources of Cytoplasmic Genetic Male Sterility, Heterosis, and Combining Ability in Pearl Millet

A Study on Sources of Cytoplasmic Genetic Male Sterility, Heterosis, and Combining Ability in Pearl Millet

AVANCE GENÉTICO EN 14 CICLOS DE SELECCIÓN RECURRENTE EN LA POBLACIÓN ANDROESTÉRIL PANDOLY.PABG DE TRIGO

El gen Oly es una fuente de androesterilidad dominante que ha permitido conformar diversas poblaciones para realizar selección recurrente en trigo (Triticum aestivum L.), tal es el caso de la población androestéril de amplia base genética denominada PANDOLY.PABG, que ha permitido derivar líneas y generar variedades. Con el objetivo de estimar el avance genético después de 14 ciclos de selección recurrente en dicha población y valorar la eficiencia del gen Oly para formar líneas superiores, se evaluaron 80 líneas F5 tomadas al azar de los ciclos C0, C2, C4, C6, C8, C10, C12 y C14 más 10 variedades testigo. Se empleó un diseño alfa-látice 9 × 10 con dos repeticiones y dos fechas de siembra durante el ciclo otoño-invierno 2017/2018 en Roque, Guanajuato y Montecillo, Estado de México. Las variables evaluadas fueron días a floración (DF), altura de planta (AP), días a madurez (DM), rendimiento de grano (RG), tasa de llenado de grano (TLLG), índice de cosecha (IC), biomasa (BIO), peso de 1000 semillas (PMS), número de espigas por m2 (EPM2), de granos por m2 (GPM2) y de granos por espiga (GPE). El mayor aumento de RG fue de 1445 kg ha-1 entre los ciclos C0 y C2. El avance genético promedio en los 14 ciclos fue de 3.58 % (140.6 kg ha-1/ciclo). Entre los cambios morfofisiológicos destacan, particularmente en los ciclos avanzados de selección, aumento (P ≤ 0.05) en los caracteres TLLG, IC, BIO, PMS, EPM2, GPM2 y GPE, y disminución (P ≤ 0.05) de DF, DM y AP. Las variedades testigo y las líneas derivadas del C14 presentaron RG más altos (P ≤ 0.05) y estadísticamente iguales. El gen Oly es un excelente facilitador del mejoramiento genético poblacional en trigo.

Genetic variability studies involving maintainers on maldandi and milo source of male sterility in rabi sorghum [Sorghum bicolor (L.) Moench

An experiment was conducted to know the variability among 22 maintainers on maldandi and milo source of male sterility in rabi sorghum along with four checks M 35-1, BJV-44, DJ6514 and PKV Kranti. The study revealed considerable amount of variability for all the characters studied. The genotypic and phenotypic coefficients of variation observed to be the highest for grain yield per-plant, the number of seeds per panicle and panicle weight. All the characters showed an arrow difference between PCV and GCV, indicating that the observed variability has been primarily due to genotypic differences with the least influence of environment. High heritability coupled with high genetic advance over mean was noticed for all the characters studied there by indicating that the selection would be effective in improvement of these characters as they are controlled by the additive genes. Based on mean performance the genotypes IS 14010 and IS 19445 were found significantly superior over the checks M35-1 and DJ6514.