Relations between and inheritance of chlorogenic acid contents in an interspecific cross between Coffea pseudozanguebariae and Coffea liberica var ‘dewevrei’

 Chlorogenic acids (CGA) are phenolic compounds commonly found in green coffee beans. The main CGA classes are caffeoylquinic acids (CQA), dicaffeoylquinic acids (diCQA), and feruloylquinic acids (FQA). Each contains three isomers differing in the number and identity of the acylating residues. An interspecific cross between Coffea pseudozanguebariae (low CGA content) and C. liberica var ‘dewevrei’ (high CGA content) was investigated for CGA contents in F₁ and back-cross hybrids. Relations within and between CGA classes were studied and confirmed the known biosynthesis pathway. A single major gene was noted for the 3-FQA isomer; absence was dominant. Additivity was found for most other isomers either with or without the transformation of variables. Conversely, most ratios were not additive, due to a curvilinear relation between some isomers. The consequences for breeding both in terms of cup taste improvement and disease resistance are discussed. Received: 20 July 1998 / Accepted: 14 August 1998     

Assaying polymorphism at DNA level for genetic diversity diagnostics of the safflower (Carthamus tinctorius L.) world germplasm resources

Carthamus tinctorius (2n = 2x = 24), commonly known as safflower, is widely cultivated in agricultural production systems of Asia, Europe, Australia, and the Americas as a source of high quality vegetable and industrial oil. Twenty-two RAPD primers, 18 SSR primers, and 10 AFLP primer combinations were used to assess: (1) the genetic diversity of 85 accessions (originating from 24 countries) representing global germplasm variability of safflower and (2) the interrelationships among safflower ‘centers of similarity’ or ‘regional gene pools’ proposed earlier. The RAPD and SSR primers and AFLP primer combinations revealed 57.6, 68.0, and 71.2% polymorphism, respectively, among 111, 72, and 330 genetic loci amplified from the accessions. The sum of effective number of alleles (66.44), resolving power (59.16), and marker index (51.3) explicitly revealed the relative superiority of AFLP as a marker system in uncovering variation in safflower. Overall, AFLP markers could recognize ‘centers of similarity’ or ‘regional gene pools’. Analysis of molecular variance and Shannon’s information index provided corroborating evidences for the present and previous studies that concluded fragmentation of safflower gene pool into many gene pools. Divergent directional selection is likely to have played an important role in shaping the diversity. From the practical applications standpoint, the diversity of Iran–Afghanistan gene pool is very high, equivalent to the total diversity of the species. The Far East gene pool is the least diverse. The present comprehensive input, first of its own kind in safflower, will assist marker based improvement programmes in the crop.     

Genetic analysis of resistance to blackspot (Diplocarpon rosae) in tetraploid roses

  Diplocarpon rosae is the causal agent of rose blackspot, one of the most severe diseases of field-grown roses. The genetics of resistance to this pathogen was investigated in crosses between tetraploid rose genotypes. The hybrid breeding line 91/100-5, which exhibits a broad resistance to all isolates tested so far, was selfed to produce an F₂ population, backcrossed to the susceptible tetraploid variety ‘Caramba’ and crossed to the susceptible varieties ‘Heckenzauber’, ‘Pariser Charme’ and ‘Elina’. Infection experiments resulted in segregation ratios consistent with the presence of a single dominant resistance locus in the duplex configuration in the hybrid 91/100-5. This suggests, together with previous data on the race structure of the fungus, a “gene-for-gene” type of interaction in the pathosystem Diplocarpon/Rosa. We propose to designate this gene Rdr1, which is the first resistance gene described in the genus Rosa. The advantages and limitations of such an interaction type for future rose breeding programmes and for marker-assisted selection strategies are discussed. Received: 29 August 1997 / Accepted: 19 September 1997     

Overexpression of <Emphasis Type="Italic">TaNHX2</Emphasis> enhances salt tolerance of ‘composite’ and whole transgenic soybean plants

Salinity is a major factor resulting in extensive loss of agricultural production. Genetic transformation has become a powerful tool for studying gene function and for improving crop salt tolerance. In this study, a TaNHX2 gene was transformed into a plant cloning vector under the control of cauliflower mosaic virus 35S promoter, and then introduced into Agrobacterium rhizogenes strain K599. Explants of soybean were transformed with A. rhizogenes and ‘composite’ plants consisting of wild-type shoots and transgenic hairy roots overexpressing TaNHX2 were produced. When exposed to salt stress, ‘composite’ plants displayed high salinity tolerance at 171 mM NaCl in vermiculite and in solid medium supplemented with up to 200 mM NaCl, whereas control plants displayed chlorosis and died within 15 days under above treatment conditions. We subsequently obtained soybean plants overexpressing TaNHX2 through A. tumefaciens-mediated transformation and studied four homozygous lines of TaNHX2. Transgenic lines displayed an enhanced salt tolerance in plant biomass and flower number per plant, compared with wild type plants grown on sand culture containing 150 mM NaCl. Furthermore, transgenic plants of line C12-11 showed longer survival, less growth inhibition and greater number of flowers than wild type plants. Taken together, these results indicated that TaNHX2 gene could enhance salt tolerance of soybean, and A. rhizogenes-mediated transformation system could be used as a complementary tool of A. tumerfaciens-mediated transformation to rapidly investigate candidate gene function in soybean.     

Evolution of early determinate tomato cultivars during the last three decades as a result of research conducted at Warsaw Agricultural University

Earliness is a crucial factor of tomato field production in Poland. A. Michalska and B. Kubicki (1978) conducted the first investigations on tomato earliness at the Department of Plant Genetics and Breeding. The main conclusions from these studies indicated that it was possible to obtain varieties earlier than ‘New Yorker’ as a result of transgression. The two new varieties (‘Alfa’ and ‘Akord F₁’) proved to be two weeks earlier than ‘New Yorker’. However, earliness was correlated with smaller fruit weight (30–40 g). At the next stage of experiment some improvement was achieved both in the size of fruit (45 g for ‘Beta’ up to 70 g for ‘Alka’) as well as colour intensity and good flavour. With the next few years fruit weight was still increased (up to 100 g for ‘Maskarena’) and a higher level of firmness was obtained (mid firm fruits for ‘Maskarena’ and ‘Delta’). At present, the Polish Research Centre for Cultivar Testing recommends our varieties ‘Betalux’, ‘Promyk’ and ‘Delta’ as standards.     

Variation in performance on two grape cultivars within and among populations of grape Phylloxera from wild and cultivated habitats

When an indigenous insect becomes a pest, comparisons of performance of pest and non-pest populations on crop plants and of genetic variation in that performance may provide insight into the evolution of pest populations. To measure such genetic variation, 8–15 clones of the grape phylloxera (Daktulosphaira vitifoliae Fitch) were collected from wild grapevines in each of 3 geographically isolated sites (populations) and from commercial vineyards in northern California. A complete life table was made for clonal replicates from populations collected from wild grapevines on each of two commercial grape cultivars, the susceptibleVitis vinifera (L.) cultivar Cabernet Sauvignon, and the phylloxera-resistant rootstock ‘AxR # 1’. Variation in mean performance on these two hosts was partitioned among clones within collection sites and among sites. Performance measures included an individual analog to the intrinsic rate of increase (r), age at first oviposition, fecundity in the first ten days of reproduction, total fecundity, and longevity. The overall performance of phylloxera from the wild grapevines on the resistant cultivar AxR # 1 was greater than or equal to that on the susceptible cultivar Cabernet Sauvignon. There was significant variation among clones within populations from wild grapes in the rate of increase on ‘AxR # 1’ and marginally significant clonal variation in some of the component paramters. There was no significant variation among clones within populations on ‘Cabernet Sauvignon’ and no significant differences between populations on either crop in any trait. In a second experiment we compared the relative performance of 15–17 clones from wild grapevines and from commercial vineyards when reared on ‘Cabernet Sauvignon’ and ‘AxR # 1’. Phylloxera from commercial vineyards had much higher overall performance on ‘Cabernet Sauvignon’ than did phylloxera from the wild grapevines. Phylloxera from the commercial vineyard also had higher performance on ‘Cabernet Sauvignon’ than on ‘AxR′ 1’ but the performance of the phylloxera from wild and commercial grapes did not differ on ‘AxR # 1’. Our results show that there is genetic variation in traits related to performance on a resistant rootstock within these indigenous non-pest populations of phylloxera, but not among them. The pattern of performance of pest and non-pest populations on two commercial cultivars suggests that current levels of phylloxera performance on crop cultivars are the result of adaptation to those cultivars which has occurred while phylloxera has been associated with viticulture. Implications of these results for understanding the recent adaptation of phylloxera to ‘AxR # 1’ in California are also discussed.     

Postulation of resistance genes to barley diseases in heterogeneous varieties

Resistance to causal agents of diseases is an important varietal characteristic that influences the management practice of crop plants and thus production costs of commodities. At present, almost all European barley varieties possess at least one major gene for resistance to powdery mildew. After hybridizing selected parental varieties, resistance genes often segregate in subsequent generations and, therefore, some varieties comprise lines that differ in the number or combinations of resistance genes. The objective of this research was to describe the various methods available for postulating resistance genes to pathogens in heterogeneous varieties using resistance to powdery mildew of barley as an example. Four spring barleys (‘Orbit’, ‘Malva’, ‘Tocada’ and CLE 233), and a six-row variety of winter barley, F 12872, were screened. For postulating resistance genes, several testing procedures and many Blumeria graminis f.sp. hordei isolates were used. Minimum amounts of seed were determined and different methods of obtaining homogeneous seed samples from heterogeneous varieties were compared. It was found that ‘Orbit’ and ‘Malva’ are composed of three and ‘Tocada’, CLE 233 and F 12872 of two lines with different resistances to powdery mildew. Problems of postulating resistance genes in heterogeneous varieties and the advantages of testing leaf segments instead of young plants are discussed.     

A chimeric <Emphasis Type="Italic">Rfo</Emphasis> gene generated by intergenic recombination cosegregates with the fertility restorer phenotype for cytoplasmic male sterility in radish

In this work, we have identified a chimeric pentatricopeptide repeat (PPR)-encoding gene cosegregating with the fertility restorer phenotype for cytoplasmic male sterility (CMS) in radish. We have constructed a CMS-Rf system consisting of sterile line ‘9802A2’, maintainer line ‘9802B2’ and restorer line ‘2007H’. F₂ segregating population analysis indicated that male fertility is restored by a single dominant gene in the CMS-Rf system described above. A PPR gene named Rfoc was found in the restorer line ‘2007H’. It cosegregated with the fertility restorer in the F₂ segregating population which is composed of 613 fertile plants and 187 sterile plants. The Rfoc gene encodes a predicted protein 687 amino acids in length, comprising 16 PPR domains and with a putative mitochondrial targeting signal. Sequence alignment showed that recombination between the 5′ region of Rfob (EU163282) and the 3′ region of PPR24 (AY285675) resulted in Rfoc, indicating a recent unequal crossing-over event between Rfo and PPR24 loci at a distance of 5.5 kb. The sterile line ‘9802A2’ contains the rfob gene. In the F₂ population, Rfoc and rfob were observed to fit a segregation ratio 1:2:1 showing that Rfoc was allelic to Rfo. Previously we have reported that a fertile line ‘2006H’, which carries the recessive rfob gene, is able to restore the male fertility of CMS line ‘9802A1’ (Wang et al. in Theor Appl Genet 117:313–320, 2008). However, here when conducting a cross between the fertile line ‘2006H’ and CMS line ‘9802A2, the resulting plants were male sterile, which shows that sterile line ‘9802A2’ possesses a different nuclear background compared to ‘9802A1’. Based on these results, the genetic model of fertility restoration for radish CMS is also discussed.     

Selection of Highly Informative Microsatellite Markers to Identify Pollen Donors in ‘Hass’ Avocado Orchards

‘Hass’ is the most popular avocado (Persea americana Mill.) cultivar in the world. It has been characterized as a crop requiring cross-pollination. However, the potential extent of self-pollination and the most effective pollen donors (best cross-pollinizing cultivars) have not been determined. In this study, 56 markers were screened against ‘Hass’ and nine commonly used pollinizing cultivars grown in southern California: ‘Bacon,’ ‘Ettinger,’ ‘Fuerte,’ ‘Harvest,’ ‘Lamb Hass,’ ‘Marvel,’ ‘Nobel,’ ‘Sir Prize,’ and ‘Zutano.’ Seventeen microsatellite, i.e., simple sequence repeat (SSR) markers, were found to be very promising for paternity analysis. Four highly informative SSR markers were selected to accurately and unequivocally identify pollen parents of ‘Hass’ fruit from an orchard interplanted with these pollinizing cultivars. From 2003 to 2006, 7,984 ‘Hass’ fruit were analyzed for their paternity. Overall, the pollen parents of 99.55% of the analyzed fruit could be unequivocally identified with a single multiplex polymerase chain reaction (PCR). Only 36 fruits (<0.45%) required a second PCR reaction to reach unequivocal identification of the pollen parents.     

In vitro assay of native Iranian almond species (<Emphasis Type="Italic">Prunus</Emphasis> L. spp.) for drought tolerance

Eight native Iranian almond species from three sections, ‘Euamygdalus’ (Prunus communis; Prunus eleagnifolia and Prunus orientalis); ‘Lycioides’ (Prunus lycioides and Prunus reuteri) and ‘Spartioides’ (Prunus arabica, Prunus glauca and Prunus scoparia) were in vitro screened for drought tolerance using sorbitol and polyethylene glycol (PEG) as an osmoticum. Different levels of water stress were induced using five concentrations of either sorbitol or polyethylene glycol in Woody Plant Medium (WPM). Water potential of various media ranged from −0.80 to −2.05 MPa and water stress in culture medium adversely affected plantlet growth. Wild species from ‘Spartioides’ were less affected than ‘Lycioides’ and ‘Euamygdalus’. At the same level of water potential, sorbitol had lower adverse effects than PEG; the latter being severe. Prunus × sorbitol and Prunus × PEG interactions were significant. At 0.2 M sorbitol and 0.003 M PEG, ‘Spartioides’ produced significantly more roots with higher total root length and root volume, as well as root-dry weight than those of ‘Lycioides’ and ‘Euamygdalus.’ It is concluded that in vitro screening of native Iranian almond species under specific and limited water-stress conditions may provide a system for effectively differentiating the wild species of almond for their expected root mass production under field conditions.     

Molecular mapping of a resistance-specific PCR-based marker linked to a gall midge resistance gene (Gm4t) in rice

 A PCR-based marker (E20₅₇₀) linked to the gene Gm4t, which confers resistance to a dipteran pest gall midge (Orseolia oryzae), has been mapped using the restriction fragment length polymorphism (RFLP) technique in rice. Gm4t is a dominant resistance gene. We initially failed to detect useful polymorphism for this marker in a F₃ mapping population derived from a cross between two indica parents, ‘Abhaya’בShyamala’, with as many as 35 restriction enzymes. ‘Abhaya’ carries the resistance gene Gm4t and ‘Shyamala’ is susceptible to gall midge. Subsequently, E20₅₇₀ was mapped using another mapping population represented by a F₂ progeny from a cross between ‘Nipponbare’, a japonica variety, and ‘Kasalath’, an indica variety, in which the gene Gm4t was not known to be present. Gm4t mapped onto chromosome 8 between markers R1813 and S1633B. Our method, thus, presents an alternative way of mapping genes which otherwise would be difficult to map because of a lack of polymorphism between closely related parents differing in desired agronomic traits. Received: 1 April 1997 / Accepted: 13 May 1997     

Localization of the rice stripe disease resistance gene, Stv-bi, by graphical genotyping and linkage analyses with molecular markers

 We used graphical genotyping and linkage analyses with molecular markers to determine the chromosomal location of the rice stripe disease resistance gene, Stv-b ⁱ . The stripe resistance gene from the indica rice (Oryza sativa) cv ‘Modan’ was introgressed into several Japanese rice varieties. We found 4 RFLP markers in ‘Modan’, five susceptible parental rice varieties (‘Norin No. 8’, ‘Sachihikari’, ‘Kanto No. 98’, ‘Hokuriku No.103’ and ‘Koganebare’) and four resistant progeny varieties (‘St. No. 1’, ‘Aichi No. 6’, ‘Aoisora’ and ‘Asanohikari’). Graphical genotyping of the resistant progeny revealed a chromosomal segment ascribable to ‘Modan’ and associated with stripe resistance. The chromosomal segment from ‘Modan’ was located at 35.85 cM on chromosome 11. Linkage analysis using 120 F₂ individuals from a cross between ‘Koshihikari’ (susceptible) and ‘Asanohikari’ (resistant) revealed another 8 RFLP markers in the same chromosome. We performed a bioassay for rice stripe resistance in F₃ lines of the F₂ individuals using infective small brown planthoppers and identified an 1.8-cM segment harboring the rice stripe disease resistance gene, Stv-b ⁱ , between XNpb220 and XNpb257/ XNpb254. Furthermore, Stv-b ⁱ was linked by 0.0 cM to a RFLP marker, ST10, which was developed on the basis of the results of RAPD analysis. These DNA markers near the Stv-b ⁱ locus may be useful in marker-assisted selection and map-based cloning of the Stv-b ⁱ gene. Received: 26 September 1997 / Accepted: 4 November 1997     

A genetic linkage map for an apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) BC<Subscript>1</Subscript> population mapping <Emphasis Type="Italic">plum pox virus</Emphasis> resistance

Plum pox virus (sharka; PPV) can cause severe crop loss in economically important Prunus species such as peach, plum, apricot, and cherry. Of these species, certain apricot cultivars (‘Stark Early Orange’, ‘Goldrich’, ‘Harlayne’) display significant levels of resistance to the disease and are the genetic substrate for studies of several xlaboratories working cooperatively to genetically characterize and mark the resistance locus or loci for marker-assisted breeding. The goals of the work presented in this communication are the characterization of the genetics of PPV resistance in ‘Stark Early Orange’ and the development of co-dominant molecular markers for marker-assisted selection (MAS) in PPV resistance breeding. We present the first genetic linkage map for an apricot backcross population of ‘Stark Early Orange’ and the susceptible cultivar ‘Vestar’ that segregates for resistance to PPV. This map is comprised of 357 loci (330 amplified fragment length polymorphisms (AFLPs), 26 simple sequence repeats (SSRs), and 1 morphological marker for PPV resistance) assigned to eight linkage groups. Twenty-two of the mapped SSRs are shared in common with genetic reference map for Prunus (T × E; Joobeur et al. 1998) and anchor our apricot map to the general Prunus map. A PPV resistance locus was mapped in linkage group 1 and four AFLP markers segregating with the PPV resistance trait, identified through bulk segregant analysis, facilitated the development of SSRs in this region. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Lalli, D.A. and Salava, J. contributed equally to this work.     

Dehydrogenase and urease activities of maize (Zea mays L.) field soils

Summary Dehydrogenase and urease activities, bacterial and fungal populations and physicochemical characteristics of maize (Zea mays L.) field soils have been studied for one crop cycle. A comparison has been made among soils of three different agricultural systemsviz permanent agriculture on plain lands in valleys, recently introduced terrace land agriculture and age old ‘slash and burn’ type of shifting agriculture on slopes. Results demonstrate that the enzyme activities, microbial population as well as most of the physico-chemical characteristics of soils followed the trend permanent agriculture on plain lands>terrace land agriculture>‘slash and burn’ type of shifting agriculture. Moisture and nutrient levels and topography of the lands were found to be major factors responsible for the trend.     

<Emphasis Type="Italic">Rpv10</Emphasis>: a new locus from the Asian <Emphasis Type="Italic">Vitis</Emphasis> gene pool for pyramiding downy mildew resistance loci in grapevine

A population derived from a cross between grapevine breeding strain Gf.Ga-52-42 and cultivar ‘Solaris’ consisting of 265 F1-individuals was genetically mapped using SSR markers and screened for downy mildew resistance. Quantitative trait locus (QTL) analysis revealed two strong QTLs on linkage groups (LGs) 18 and 09. The locus on LG 18 was found to be identical with the previously described locus Rpv3 and is transmitted by Gf.Ga-52-42. ‘Solaris’ transmitted the resistance-related locus on LG 09 explaining up to 50% of the phenotypic variation in the population. This downy mildew resistance locus is named Rpv10 for resistance to Plasmopara viticola. Rpv10 was initially introgressed from Vitis amurensis, a wild species of the Asian Vitis gene pool. The one-LOD supported confidence interval of the QTL spans a section of 2.1 centi Morgan (cM) corresponding to 314 kb in the reference genome PN40024 (12x). Eight resistance gene analogues (RGAs) of the NBS–LRR type and additional resistance-linked genes are located in this region of PN40024. The F1 sub-population which contains the Rpv3 as well as the Rpv10 locus showed a significantly higher degree of resistance, indicating additive effects by pyramiding of resistance loci. Possibilities for using the resistance locus Rpv10 in a grapevine breeding programme are discussed. Furthermore, the marker data revealed ‘Severnyi’ × ‘Muscat Ottonel’ as the true parentage for the male parent of ‘Solaris’.     

A caveat in mouse genetic engineering: ectopic gene targeting in ES cells by bidirectional extension of the homology arms of a gene replacement vector carrying human PARP-1

Here we report an approach to generate a knock-in mouse model using an ‘ends-out’ gene replacement vector to substitute the murine Parp-1 (mParp-1) coding sequence (32 kb) with its human orthologous sequence (46 kb). Unexpectedly, examination of mutant ES cell clones and mice revealed that site-specific homologous recombination was mimicked in three independently generated ES cell clones by bidirectional extension of the vector homology arms using the endogenous mParp-1-flanking sequences as templates. This was followed by adjacent integration of the targeting vector, thus leaving the endogenous mParp-1 locus functional. A related phenomenon termed ‘ectopic gene targeting’ has so far only been described for ‘ends-in’ integration-type vectors in non-ES cell gene targeting. We provide reliable techniques to detect such ectopic gene targeting which represents an unexpected caveat in mouse genetic engineering that should be considered in the design and validation strategy of future gene knock-in approaches. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Rapid shoot regeneration in industrial ‘high starch’ sweetpotato (<Emphasis Type="Italic">Ipomoea batatas</Emphasis> L.) genotypes

Sweetpotato (Ipomoea batatas L.) is an important crop in North Carolina with annual production of 0.33 million tons, accounting for 37% of total US supply (USDA, Louisiana Farm Reporter 8(12), August 2008). To target industrial use, novel high-starch industrial-type varieties that contain more than 30% dry matter were developed by conventional breeding methods. In vitro cultures from selected genotypes were established using meristem culture. To establish regeneration procedures that could be coupled with transformation experiments, conditions for the induction of rapid shoot-organogenesis in leaf explants were compared using varying concentrations of the auxins ‘NAA’, ‘IAA’, ‘2,4-D’, and ‘4-FA’ either alone or in combination with zeatin riboside. Regeneration efficiencies, defined as the number of explants developing shoots out of the total number tested, were as high as 57% for the best genotypes, with a significant genotype-dependent response observed in all the hormone regimes evaluated. In all treatments, shoot regeneration was observed within 2 months. Our results led to the establishment of optimized in vitro regeneration procedures for the novel high-starch sweetpotato (SP) genotypes ‘DM01-158’, ‘FTA94’, ‘FT489’, and ‘PDM P4’ that are rapid and reliable.     

Isolation,Characterization, and Expression Analysis of an <Emphasis Type="Italic">SKP1-</Emphasis>like Gene from ‘Shatian’ Pummelo (<Emphasis Type="Italic">Citrus grandis</Emphasis> Osbeck)

Plant s-phase kinase-associated protein 1 (SKP1) genes have diverse functions in plant developmental and physiological activities. Herein, we described a novel SKP1 gene, designated as CgSKP1, from ‘Shatian’ pummelo (Citrus grandis Osbeck). The cDNA sequence of CgSKP1 was 603 bp and contained an open reading frame of 477 bp. Genomic sequence of the CgSKP1 gene contained two exons and one intron. The predicted amino acid sequence of this gene is consisted of 158 amino acids with theoretical proteins size of 17.9 kDa. CgSKP1 had high identity with SKP1 genes from other plant species within two conserved region. Full-length cDNAs were also amplified and cloned from six citrus varieties, with 95% nucleotide identity and about 98% amino acid similarity among them. Gel blot analysis suggested that CgSKP1 existed as a single locus in the ‘Shatian’ pummelo genome. The expression of CgSKP1 was gradually increased during flower developmental stages in ‘Shatian’ pummelo. Moreover, expression analysis by RT-PCR, qRT-PCR and in situ hybridization of CgSKP1 showed that it was highly expressed in the leaf, petal, anther and ovary, but lowly in the style. These findings indicated that CgSKP1 was closely related to ‘Shatian’ pummelo flower development.