Comparison of the genetic determinism of two key phenological traits,flowering and maturity dates,in three Prunus species: peach,apricot and sweet cherry

The present study investigates the genetic determinism of flowering and maturity dates, two traits highly affected by global climate change. Flowering and maturity dates were evaluated on five progenies from three Prunus species, peach, apricot and sweet cherry, during 3–8 years. Quantitative trait locus (QTL) detection was performed separately for each year and also by integrating data from all years together. High heritability estimates were obtained for flowering and maturity dates. Several QTLs for flowering and maturity dates were highly stable, detected each year of evaluation, suggesting that they were not affected by climatic variations. For flowering date, major QTLs were detected on linkage groups (LG) 4 for apricot and sweet cherry and on LG6 for peach. QTLs were identified on LG2, LG3, LG4 and LG7 for the three species. For maturity date, a major QTL was detected on LG4 in the three species. Using the peach genome sequence data, candidate genes underlying the major QTLs on LG4 and LG6 were investigated and key genes were identified. Our results provide a basis for the identification of genes involved in flowering and maturity dates that could be used to develop cultivar ideotypes adapted to future climatic conditions.     

Mapping Architectural, Phenological, and Fruit Quality QTLs in Apricot

The F1 population “Harostar”?×?“Rouge de Mauves” was used to perform a quantitative trait loci (QTL) mapping for tree architecture traits (i.e., tree diameter, total branch number, tree shape); time to initial reproductive bud break; and fruit quality traits (i.e., ground color, fruit form, soluble solid content) using data collected from 2010 to 2012. For architectural traits, interval mapping detected QTLs only in “Rouge de Mauves” on linkage group 1 for trunk diameter in 2010, on LG6 for total branch number in 2010, and on LG1 and LG5 for tree shape for both years 2010 and 2011 combined. QTLs were detected only in “Harostar” for time to initial reproductive bud break on LG1 and LG4 in 2011. For fruit quality traits, data were collected in 2011 and 2012. QTLs were identified on LG1 in 2011 and on LG4 in 2012 for soluble solid content, on LG3 for ground color in both years, on LG7 only in 2011, and on LG3 for fruit form in both years. The QTLs that we identified were compared to those previously identified in other Prunus spp.     

Selection on domestication traits and quantitative trait loci in crop-wild sunflower hybrids

The strength and extent of gene flow from crops into wild populations depends, in part, on the fitness of the crop alleles, as well as that of alleles at linked loci. Interest in crop-wild gene flow has increased with the advent of transgenic plants, but nontransgenic crop-wild hybrids can provide case studies to understand the factors influencing introgression, provided that the genetic architecture and the fitness effects of loci are known. This study used recombinant inbred lines (RILs) generated from a cross between crop and wild sunflowers to assess selection on domestication traits and quantitative trait loci (QTL) in two contrasting environments, in Indiana and Nebraska, USA. Only a small fraction of plants (9%) produced seed in Nebraska, due to adverse weather conditions, while the majority of plants (79%) in Indiana reproduced. Phenotypic selection analysis found that a mixture of crop and wild traits were favoured in Indiana (i.e. had significant selection gradients), including larger leaves, increased floral longevity, larger disk diameter, reduced ray flower size and smaller achene (seed) mass. Selection favouring early flowering was detected in Nebraska. QTLs for fitness were found at the end of linkage groups six (LG6) and nine (LG9) in both field sites, each explaining 11-12% of the total variation. Crop alleles were favoured on LG9, but wild alleles were favoured on LG6. QTLs for numerous domestication traits overlapped with the fitness QTLs, including flowering date, achene mass, head number, and disk diameter. It remains to be seen if these QTL clusters are the product of multiple linked genes, or individual genes with pleiotropic effects. These results indicate that crop trait values and alleles may sometimes be favoured in a noncrop environment and across broad geographical regions.     

In Loquat (Eriobotrya japonica Lindl.) Return Bloom Depends on the Time the Fruit Remains on the Tree

In loquat (Eriobotrya japonica Lindl.), the comparison of fruiting trees and defruited trees carried out covering a range of developmental fruit stages reveals a significant reduction in flowering due to fruit from its early stage of development, being higher when it changes color and becomes senescent, which coincides with the floral bud inductive period. This effect occurred both at the tree and at the shoot level. Furthermore, although current shoots almost always develop into panicles, those from fruiting trees develop fewer flowers, suggesting that fruit also affects at the floral bud level. In our experiment, the gibberellin concentration at the floral bud inductive period was significantly higher in bark tissues (periderm, cortex and phloem tissues) of fruiting trees, compared with defruited trees that tend to flower more. The lower concentration of IAA in the bark tissues of defruited trees also contributes to increase their flowering intensity. On the contrary, the zeatin concentration was higher. Accordingly, at bud burst, the IAA/zeatin ratio, an indication of effect on flowering, was significantly higher for fruiting trees. Some disruption in the nitrate reduction process in fruiting tree was also observed. The process of floral bud induction and differentiation was not associated with either reducing or translocating and reserve carbohydrate concentration. Hence, loquat flower intensity depends on the time the fruit is maintained on the tree. The intensity is affected indirectly, by reducing the number of shoots, and directly, by reducing the number of flowers per panicle, and these effects are linked to endogenous plant hormone contents.     

Selection on domestication traits and quantitative trait loci in crop–wild sunflower hybrids

The strength and extent of gene flow from crops into wild populations depends, in part, on the fitness of the crop alleles, as well as that of alleles at linked loci. Interest in crop–wild gene flow has increased with the advent of transgenic plants, but nontransgenic crop–wild hybrids can provide case studies to understand the factors influencing introgression, provided that the genetic architecture and the fitness effects of loci are known. This study used recombinant inbred lines (RILs) generated from a cross between crop and wild sunflowers to assess selection on domestication traits and quantitative trait loci (QTL) in two contrasting environments, in Indiana and Nebraska, USA. Only a small fraction of plants (9%) produced seed in Nebraska, due to adverse weather conditions, while the majority of plants (79%) in Indiana reproduced. Phenotypic selection analysis found that a mixture of crop and wild traits were favoured in Indiana (i.e. had significant selection gradients), including larger leaves, increased floral longevity, larger disk diameter, reduced ray flower size and smaller achene (seed) mass. Selection favouring early flowering was detected in Nebraska. QTLs for fitness were found at the end of linkage groups six (LG6) and nine (LG9) in both field sites, each explaining 11–12% of the total variation. Crop alleles were favoured on LG9, but wild alleles were favoured on LG6. QTLs for numerous domestication traits overlapped with the fitness QTLs, including flowering date, achene mass, head number, and disk diameter. It remains to be seen if these QTL clusters are the product of multiple linked genes, or individual genes with pleiotropic effects. These results indicate that crop trait values and alleles may sometimes be favoured in a noncrop environment and across broad geographical regions.     

An AFLP, SRAP, and SSR Genetic Linkage Map and Identification of QTLs for Fruit Traits in Pear (Pyrus L.)

In this study, a population of 97 F₁ seedlings from a cross between the interspecific hybrid (European × Chinese species) pear ‘Bayuehong’ (BYH) and the Chinese pear ‘Dangshansuli’ (DS) was used for establishing linkage maps and for quantitative trait loci (QTL) discovery. Using amplified length polymorphism (AFLP), simple sequence repeat (SSR), and sequence-related amplified polymorphism (SRAP) markers, along with the S locus for self-incompatibility, two parental linkage maps were constructed. The map of BYH consisted of 214 markers (143 AFLPs, 64 SRAPs, 6 SSRs, and S) mapped on all 17 linkage groups of the pear genome with a total length of 1,352.7 cM. The map of DS was comprised of 122 markers (83 AFLPs, 37 SRAPs, 1 SSR, and S) distributed along all 17 linkage groups and covering 1,044.3 cM. Based on phenotypic data from two successive years (2007 and 2008) for six fruit traits, including fruit weight (in grams), fruit diameter (in centimeters), fruit length (in centimeters), soluble solids content, fruit shape index, and maturity date, 19 QTLs were detected. These QTLs were mapped on LG 01, LG 02, LG 05, LG 07, LG 08, LG 10 of the BYH map and LG 02, LG 06, LG 15 of the DS map and accounting for 7.1 to 22.0 % of the observed phenotypic variance. Four QTLs, Pfi-8-1 for fruit shape index, Pfm-8-1 for fruit maturity date, Pfw-7-1 and Pfw-8-1 for fruit weight (in grams), with LOD scores ≥3.5, were deemed as major genes. QTLs Pfi-8-1, Pfm-8-1, and Pfw-8-1 were co-localized on LG 08 of the BYH map, along with Pfl-8-1 for fruit length. It was observed that on LG 07 of the BYH map, QTLs for fruit length, fruit shape index, and fruit weight were clustered. When QTL locations from both years were compared, Pfl-7-1 and Pfl-7-2 for fruit length, Pfi-2-1 and Pfi-2-2 for fruit shape index, and Pfm-8-1 and Pfm-8-2 for fruit maturity date were stably mapped onto the same linkage groups, respectively. Moreover, Pfm-8-1 and Pfm-8-2 were also located within the same region of LG 08 of the BYH map.     

Mapping and characterisation of QTL × E interactions for traits determining grain and stover yield in pearl millet

A mapping population of 104 F(3) lines of pearl millet, derived from a cross between two inbred lines H 77/833-2 x PRLT 2/89-33, was evaluated, as testcrosses on a common tester, for traits determining grain and stover yield in seven different field trials, distributed over 3 years and two seasons. The total genetic variation was partitioned into effects due to season (S), genotype (G), genotype x season interaction (G x S), and genotype x environment-within-season interaction [G x E(S)]. QTLs were determined for traits for their G, G x S, and G x E(S) effects, to assess the magnitude and the nature (cross over/non-crossover) of environmental interaction effects on individual QTLs. QTLs for some traits were associated with G effects only, while others were associated with the effects of both G and G x S and/or G, G x S and G x E(S) effects. The major G x S QTLs detected were for flowering time (on LG 4 and LG 6), and mapped to the same intervals as G x S QTLs for several other traits (including stover yield, harvest index, biomass yield and panicle number m(-2)). All three QTLs detected for grain yield were unaffected by G x S interaction however. All three QTLs for stover yield (mapping on LG 2, LG 4 and LG 6) and one of the three QTLs for grain yield (mapping on LG 4) were also free of QTL x E(S) interactions. The grain yield QTLs that were affected by QTL x E(S) interactions (mapping on LG 2 and LG 6), appeared to be linked to parallel QTL x E(S) interactions of the QTLs for panicle number m(-2) on (LG 2) and of QTLs for both panicle number m(-2) and harvest index (LG 6). In general, QTL x E(S) interactions were more frequently observed for component traits of grain and stover yield, than for grain or stover yield per se.     

Comparison of Flowering Time Genes in Brassica Rapa, B. Napus and Arabidopsis Thaliana

The major difference between annual and biennial cultivars of oilseed Brassica napus and B. rapa is conferred by genes controlling vernalization-responsive flowering time. These genes were compared between the species by aligning the map positions of flowering time quantitative trait loci (QTLs) detected in a segregating population of each species. The results suggest that two major QTLs identified in B. rapa correspond to two major QTLs identified in B. napus. Since B. rapa is one of the hypothesized diploid parents of the amphidiploid B. napus, the vernalization requirement of B. napus probably originated from B. rapa. Brassica genes also were compared to flowering time genes in Arabidopsis thaliana by mapping RFLP loci with the same probes in both B. napus and Arabidopsis. The region containing one pair of Brassica QTLs was collinear with the top of chromosome 5 in A. thaliana where flowering time genes FLC, FY and CO are located. The region containing the second pair of QTLs showed fractured collinearity with several regions of the Arabidopsis genome, including the top of chromosome 4 where FRI is located. Thus, these Brassica genes may correspond to two genes (FLC and FRI) that regulate flowering time in the latest flowering ecotypes of Arabidopsis.     

Inheritance of reproductive phenology traits and related QTL identification in apricot

Reproductive phenological traits of great agronomical interest in apricot species, including flowering date, ripening date and fruit development period, were studied during 3 years in two F₁ progenies derived from the crosses ‘Bergeron’ × ‘Currot’ (B × C) and ‘Goldrich’ × ‘Currot’ (G × C). Results showed great variability and segregation in each population, confirming the polygenic nature and quantitative inheritance of all the studied traits. Genetic linkage maps were constructed combining SSR and SNP markers, using 87 markers in the ‘B × C’ population and 89 markers in ‘G × C’. The genetic linkage maps in both progenies show the eight linkage groups (LGs) of apricot, covering a distance of 394.9 cM in ‘Bergeron’ and of 414.3 cM in ‘Currot’. The ‘Goldrich’ and ‘Currot’ maps were of 353.5 and 422.3 cM, respectively. The average distance obtained between markers was thus 7.59 cM in ‘Bergeron’ and 7.53 cM in ‘Currot’, whereas the ‘Goldrich’ and ‘Currot’ averages were 5.6 and 7.5 cM, respectively. According to the polygenic nature of the studied phenology traits, QTLs linked to flowering date, ripening date and the fruit development period were identified during the 3 years of the study in all LGs except for LG 8. Among the QTLs identified, major QTLs for flowering and ripening date and the fruit development period were identified in LG 4, especially important in the ‘G × C’ population.     

Correlation of ovary and leaf spermidine and spermine content with the alternate bearing habit of olive

In order to investigate the possible role of the polyamines spermidine and spermine, in the alternate bearing habit of the olive, a comparative analysis of their content in vegetative and reproductive organs during the flowering period of the 'on' and 'off' years, was conducted. Samples of flowers, ovaries and leaves from two cultivars, the biennial bearer 'Chondrolia Chalkidikis' and the regular cropping 'Koroneiki' were used and the free and conjugated forms of polyamines were detected. In addition, the concentrations of K(+) and Ca(2+) were determined in all samples. Spermidine conjugates were predominant in all samples, while free spermine was not detectable. Conjugated forms of both spermidine and spermine were accumulated in ovaries, rather than in other floral tissues (corolla and stamens). They also, accumulated in significantly higher concentrations in ovaries and leaves of both cultivars, during the 'on' compared with the 'off' year, and in much higher concentrations, during the 'on' year, in ovaries of the strong alternate bearer 'Chondrolia Chalkidikis' than in 'Koroneiki'. Free spermidine was detected in ovaries and leaves of both cultivars, showing a decline during ovule fertilization in both years. Such a decline was not always recorded for the conjugated forms, depending on the organ studied and the flower load. A relation between endogenous spermidine and spermine with the K(+) or Ca(2+) composition was not established.     

Effects of floral display and plant abundance on fruit production of Ryncholaelia glauca (Orchidaceae)

Flowering plant density can increase number of visits and fruit set in multi-flowering plants, however this aspect has not been studied on few flower species. We studied the effects of individual floral display and plant density on the fruit production of the epiphytic, moth-pollinated orchid, Ryncholaelia glauca, in an oak forest of Chavarrillo, Veracruz, Mexico. Species is non-autogamous, and produced one flower per flowering shoot each flowering season. We hypothesized that orchids with more flowering shoots and those on trees with clumps of conspecific should develop more fruits than isolated ones. R. glauca population flowers synchronouly, and individual flowers last up to 18 days, with flowers closing rapidly after pollination. Individuals produced few flowers per year, although some plants developed flowers in both seasons and fewer of them developed fruits both years. There was no relationship between flower number per orchid, or per host tree, with the number of fruits developed per plant. Host trees with flowering and fruiting orchids were randomly dispersed and the pattern of distribution of flowering and fruiting plants was not related. Apparently, pollinators visit the flowers randomly, with no evidence of density dependence. The fruit set of R. glauca was as low as fruit set of multi-flowered orchids moth pollinated, suggesting that fruit set on moth pollinated orchids could be independent of the number of flowers displayed.     

Phenological variation in fruit characteristics in vertebrate-dispersed plants

Summary We investigated inter-specific variation in fruit characteristics — fruit size, seed number per fruit, seed weight, nutritional content, fruit persistence, and fruit synchronization — in relation to flowering and fruiting phenology in 34 species of fleshy fruited plants. Except for aspects of fruit synchrony and persistence, the results in general were inconsistent with previous suggestions about adaptive variation in phenologically related fruit traits. The main results were as follows: (1) Late flowering, late fruiting, lengthy development time from flower to fruit, and highly persistent fruits constitute a complex of correlated characteristics among the species. (2) Synchronization of fruiting within individuals increased from early ripening fruits to late ripening fruits. Fruiting synchrony was more pronounced in species with a small crop size than in species with a large fruit crop, whereas synchrony was not significantly related to flowering synchronization, nor to life form. (3) Nitrogen and carbohydrate content of fruit pulp did not vary in relation to phenology, whereas lipid content decreased from early to late ripening fruits. (4) No seasonal trends were found for variation in seed size or seed number per fruit. (5) Interactions with flowering phenology and developmental constraints are important in phenological fruiting patterns. Temporal variation in start of fruiting was partly (36%) explained by variation in flowering time. Seed weight variation explained 17% of variation in development time from flower to fruit. (6) Despite constraints from flowering and seed development, some adaptive adjustment in fruiting phenology is likely to be allowed for among the investigated species. Such an adaptive variation in fruiting phenology was suggested by intra-generic comparisons of Prunus and Vaccinium species.     

Mapping loci controlling vernalization requirement in Brassica rapa

Brassica cultivars are classified as biennial or annual based on their requirement for a period of cold treatment (vernalization) to induce flowering. Genes controlling the vernalization requirement were identified in a Brassica rapa F₂ population derived from a cross between an annual and a biennial oilseed cultivar by using an RFLP linkage map and quantitative trait locus (QTL) analysis of flowering time in F₃ lines. Two genomic regions were strongly associated with variation for flowering time of unvernalized plants and alleles from the biennial parent in these regions delayed flowering. These QTLs had no significant effect on flowering time after plants were vernalized for 6 weeks, suggesting that they control flowering time through the requirement for vernalization. The two B. rapa linkage groups containing these QTLs had RFLP loci in common with two B. napus linkage groups that were shown previously to contain QTLs for flowering time. An RFLP locus detected by the cold-induced gene COR6.6 cloned from Arabidopsis thaliana mapped very near to one of the B. rapa QTLs for flowering time.     

WITHIN- AND AMONG-TREE VARIATION IN FLOWER AND FRUIT PRODUCTION IN TWO SPECIES OF CARYA (JUGLANDACEAE)

The patterns of variability in the production of staminate inflorescences, pistillate flowers, and fruits for Carya ovata (Mill.) K. Koch and C. tomentosa (Poir.) Nutt. at Hutcheson Memorial Forest (Somerset County, New Jersey) were examined over a four-year period. We sought to determine 1) the patterns of variability in flowering and fruiting (within-trees, among-trees, and between-years), 2) if variable flowering might account for observed nut-bearing patterns, and 3) what were the relative contributions of intrinsic (genetic) and/or extrinsic (environmental) factors in determining flower production and fruit set. In general, our fine-scale analysis of shoots within canopies did not reveal a distinct mast fruiting pattern. While the number of male and female flowers varied significantly (among trees and between years), fruit set was not markedly affected. Variability of flowering and fruiting among shoots within trees was low. Both flowering and fruiting were observed to have a strong genetic and/or microenvironmental basis; however, flowering appeared more plastic and thus more sensitive to yearly environmental vagaries than did fruiting. Favorable environmental conditions at the time of flower differentiation may result in increased flower production; but, this does not necessarily result in increased fruit set. Many pistillate flowers abscise around the time of pollination and fertilization, apparently adjusting fruit set to available shoot resources. Approximately 50% of the pistillate flowers of both species fail to set fruit. Overall, individual trees exhibit their own flowering and fruiting schedules, suggesting the need to account for this level of variability in future studies of mast fruiting.     

Identification of QTLs Associated with Conversion of Sucrose to Hexose in Mature Fruit of Japanese Pear

Sweetness is the most important trait for fruit breeding and is fundamentally determined by both total and individual sugar contents. We analyzed the contents of sucrose, fructose, glucose, and sorbitol in mature fruit in an F₁ population derived from crossing modern Japanese pear cultivar ‘Akizuki’ and breeding line ‘373-55’. A genetic linkage map was constructed using simple sequence repeats (SSRs) and single-nucleotide polymorphisms (SNP). We identified two regions associated with individual sugar contents on linkage group (LG) 1 and LG 7. The percentages of the variance in sucrose, fructose, and glucose explained by the quantitative trait loci (QTLs) were 26.6, 15.9, and 18.5%, respectively, for the region on LG 1, and 22.2, 20.0, and 9.5%, respectively, for the region on LG 7. In both regions, genotypes associated with increases in sucrose were associated with decreases in both fructose and glucose. The 1.5-LOD support intervals of the QTLs on LGs 1 and 7 include SSRs within the regions flanking acid invertase genes PPAIV3 and PPAIV1, respectively. Because acid invertase is a key enzyme in the conversion of sucrose to hexose, these are promising candidates for genes underlying those QTLs and controlling individual sugar contents. We also found one region on LG 11 that explained 21.4% of the variation in total sugar content but was not significantly associated with variation for individual sugars. The information obtained in this study will accelerate research and breeding programs to improve fruit sweetness.     

Cattle change plant reproductive phenology,promoting community changes in a post-fire Nothofagus forest in northern Patagonia,Argentina

Aims Variations in rates and length of flowering and fruiting not only affect the reproduction of a given plant species but also the behavior and reproduction of associated taxa. Flowering and fruiting variations may be influenced by herbivory, especially by large mammals. The aim of this study was to determine the effects of cattle browsing on the reproductive phenology of understory species in a subalpine post-fire Nothofagus forest in Patagonia.Methods The effects of herbivory on plant reproductive phenology were studied in a set of experimental exclosures (fenced plots) installed since 2001 in a post-fire N. pumilio forest, located in Nahuel Huapi National Park (NHNP), Argentina. We monitored the beginning and duration of each reproductive phenological stage: floral bud, open flower, immature fruit and mature fruit. We also counted the number of flowers, fruits, seeds and viable seeds of the dominant plants to assess whether browsing modifies temporal patterns of the flowering and fruiting periods.Important findings Cattle reduced the total number of species flowering and fruiting and changed the reproductive phenology of some species. We found that palatable species seem to be negatively affected by browsing in terms of reduced fitness due to changes in flowering and fruiting periods. In contrast, cattle benefitted the reproduction of non-palatable species and could promote the invasion of shade-intolerant exotic forbs such as Cirsium vulgare. The effects of livestock reported in this study are important to understanding how browsing could alter native species establishment and possibly alter successional trajectories during recolonization after fire.     

茄子分子遗传图谱的构建及果实性状的QTL定位

以茄子(Solanum melongena)材料09-101-M和10TL-102-F4-1的重组自交系(RIL)为作图群体,构建总长度为991.7c M、共包含16个连锁群157个位点、平均图距为6.32 c M的遗传图谱。应用复合区间作图法(CIM),共检测到18个与茄子果实性状相关的QTLs,其中10个为主效QTLs,8个QTLs在两年两点的实验中能够被重复检测到。在所有QTLs中,控制果重的QTL fw1.1的效应值最大,为23.8%–31.6%,被定位在LG01(E09)上E25M34–E33M57b区域内;果长、果径与果重显著相关,且控制果长、果径与果重的QTL位于同一连锁群的相同区域。     

Mapping quantitative trait loci in chickpea associated with time to flowering and resistance to Didymella rabiei the causal agent of Ascochyta blight

Drought is the major constraint to chickpea (Cicer arietinum L.) productivity worldwide. Utilizing early-flowering genotypes and advancing sowing from spring to autumn have been suggested as strategies for drought avoidance. However, Ascochyta blight (causal agent: Didymella rabiei (Kov.) v. Arx.) is a major limitation for chickpea winter cultivation. Most efforts to introgress resistance to the pathogen into Kabuli germplasm resulted in relatively late flowering germplasm. With the aim to explore the feasibility of combining earliness and resistance, RILs derived from a cross between a Kabuli cultivar and a Desi accession were evaluated under field conditions and genotyped with SSR markers. Three quantitative trait loci (QTLs) with significant effects on resistance were identified: two linked loci located on LG4 in epistatic interaction and a third locus on LG8. Two QTLs were detected for time to flowering: one in LG1 and another on LG2. When resistance and time to flowering were analyzed together, the significance of the resistance estimates obtained for the LG8 locus increased and the locus effect on days to flowering, previously undetected, was significantly different from zero. The identification of a locus linked both to resistance and time to flowering may account for the correlation observed between these traits in this and other breeding attempts.     

Identification of Members of the Dimocarpus Longan Flowering Locus T Gene Family with Divergent Functions in Flowering

Dimocarpus longan is a subtropical fruit crop whose year-round production relies on the application of KClO₃ to induce flowering; however, the mechanism by which this chemical causes flowering is yet unknown. To further characterize floral signaling in this species, we have isolated three longan FLOWERING LOCUS T (FT)-like genes and studied their activities by heterologous expression in Arabidopsis. Expression of two of these genes (DlFT2 and DlFT3) accelerates flowering, whereas expression of the third gene (DlFT1) causes delayed flowering and produced floral morphology defects. This anti-florigenic protein may be a member of a class of FT-like family involved in flowering time control in biennial and perennial species. Surprisingly, KClO₃ treatment also suppressed the expression of both DlFT2 and DlFT3 in a field trial.