Alleles on the two dwarfing loci on 4B and 4D are main drivers of FHB‐related traits in the Canadian winter wheat population “Vienna” × “25R47”

Fusarium head blight (FHB), leaf rust and stem rust are among the most destructive wheat diseases. High‐yielding, native disease resistance sources are available in North America. The objective of this study was to map loci associated with FHB traits, leaf rust, stem rust and plant height in a “Vienna”/”25R47” population. DArT markers were used to generate a genetic map, and quantitative trait loci (QTL) analysis was performed by evaluating 113 doubled haploid lines across three environments in Ontario, Canada. FHB resistance QTL were identified on chromosomes 4D, 4B, 2D and 7A, while a QTL for leaf and stem rust resistance was identified on chromosome 1B. The dwarfing alleles of both Rht‐B1 and Rht‐D1 were associated with increased FHB index and DON content.     

Use of non‐adapted quantitative trait loci for increasing Fusarium head blight resistance for breeding semi‐dwarf wheat

Semi‐dwarf wheat is an important prerequisite for releasing a successful commercial cultivar in high‐yielding environments. In Northern Europe, this aim is achieved by using one of the dwarfing genes Rht‐B1 (formerly known as Rht‐1) or Rht‐D1 (Rht‐2). Both genes, however, result in a higher susceptibility to Fusarium head blight (FHB). We analysed the possibility to use the two non‐adapted FHB resistance quantitative trait loci Fhb1 and Fhb5 (syn. QFhs.ifa‐5A) to counterbalance the negative effect of the dwarfing allele Rht‐D1b in a winter wheat population of 585 doubled‐haploid (DH) lines segregating for the three loci. All lines were inoculated with Fusarium culmorum at four locations and analysed for FHB severity, plant height, and heading date. The DH population showed a significant (p < 0.001) genotypic variation for FHB severity ranging from 3.6% to 65.9% with a very high entry‐mean heritability of 0.95. The dwarfing allele Rht‐D1b reduced plant height by 24 cm, but nearly doubled the FHB susceptibility (24.74% vs. 12.74%). The resistance alleles of Fhb1 and Fhb5 reduced FHB susceptibility by 6.5 and 11.3 percentage points, respectively. Taken all three loci together, Fhb5 alone was already able to reduce FHB susceptibility to the same extent as Rht‐D1b increased it. This opens new avenues for selecting semi‐dwarf wheat by marker‐assisted introgression of Fhb5 without the enhancement of FHB susceptibility.     

Gene expression analysis of four WIR1-like genes in floret tissues of European winter wheat after challenge with <Emphasis Type="Italic">G. zeae</Emphasis>

Fusarium head blight (FHB) is a highly destructive disease of wheat and other cereals which causes serious mycotoxin contaminations of grain. A number of molecular mapping studies led to the detection of QTL with small to moderate effects on FHB resistance in European winter wheat. Genes involved in the defence reaction of these genotypes remain largely unknown. WIR1 (wheat induced resistance 1) genes have been shown to be upregulated in cereals during attack of various fungal pathogens; however, their role in resistance is ambiguous. In this study, the expression of three WIR1 genes and a gene with high sequence similarity to WIR1 was investigated in European winter wheat genotypes after inoculation with Giberella zeae. Floret tissues of four winter wheat genotypes (Dream, Lynx, G16-92, Hussar) were challenged with G. zeae conidia or water (control) and sampled six times during 0–96 h after inoculation. Quantitative real-time PCR showed that all four genes were highly upregulated in the resistant genotypes compared to the susceptible ones. WIR1b and a gene with sequence similarity to WIR1 genes mapped to chromosome 5DS in the G16-92/Hussar mapping population. Two genes annotated as WIR1a mapped in the interval of a FHB resistance QTL on chromosome 7BS in the Dream/Lynx mapping population. These could be considered possible candidate genes for quantitative FHB resistance.     

Genotype analysis of the wheat semidwarf Rht‐B1b and Rht‐D1b ancestral lineage

In wheat, semidwarfism resulting from reduced height (Rht)‐B1b and Rht‐D1b was integral to the ‘green revolution’. The principal donors of these alleles are ‘Norin 10’, ‘Seu Seun 27’ and ‘Suwon 92’ that, according to historical records, inherited semidwarfism from the Japanese landrace ‘Daruma’. The objective of this study was to examine the origins of Rht‐B1b and Rht‐D1b by growing multiple seed bank sources of cultivars comprising the historical pedigrees of the principal donor lines and scoring Rht‐1 genotype and plant height. This revealed that ‘Norin 10’ and ‘Suwon 92’ sources contained Rht‐B1b and Rht‐D1b, but the ‘Seu Seun 27’ source did not contain a semidwarf allele. Neither Rht‐B1b nor Rht‐D1b could be definitively traced back to ‘Daruma’, and both ‘Daruma’ sources contained only Rht‐B1b. However, ‘Daruma’ remains the most likely donor of Rht‐B1b and Rht‐D1b. We suggest that the disparity between historical pedigrees and Rht‐1 genotypes occurs because the genetic make‐up of seed bank sources differs from that of the cultivars actually used in the pedigrees. Some evidence also suggests that an alternative Rht‐D1b donor may exist.     

Effect of Rht Alleles on the Tolerance of Wheat Grain Set to High Temperature and Drought Stress During Booting and Anthesis

Factorial pot experiments were conducted to compare the responses of GA‐sensitive and GA‐insensitive reduced height (Rht) alleles in wheat for susceptibility to heat and drought stress during booting and anthesis. Grain set (grains/spikelet) of near‐isogenic lines (NILs) was assessed following three day transfers to controlled environments imposing day temperatures (t) from 20 to 40 °C. Transfers were during booting and/or anthesis and pots maintained at field capacity (FC) or had water withheld. Logistic responses (y = c/1+e^{‐b(t ‐m)}) described declining grain set with increasing t, and t₅ was that fitted to give a 5 % reduction in grain set. Averaged over NIL, t₅ for anthesis at FC was 31.7 ± 0.47 °C (S.E.M., 26 d.f.). Drought at anthesis reduced t₅ by <2 °C. Maintaining FC at booting conferred considerable resistance to high temperatures (t₅ = 33.9 °C) but booting was particularly heat susceptible without water (t₅ = 26.5 °C). In one background (cv. Mercia), for NILs varying at the Rht‐D1 locus, there was progressive reduction in t₅ with dwarfing and reduced gibberellic acid (GA) sensitivity (Rht‐D1a, tall, 32.7 ± 0.72; Rht‐D1b, semi‐dwarf, 29.5 ± 0.85; Rht‐D1c, severe dwarf, 24.2 ± 0.72). This trend was not evident for the Rht‐B1 locus or for Rht‐D1b in an alternative background (Maris Widgeon). The GA‐sensitive severe dwarf Rht12 was more heat tolerant (t₅ = 29.4 ± 0.72) than the similarly statured GA‐insensitive Rht‐D1c. The GA‐sensitive, semidwarfing Rht8 conferred greater drought tolerance in one experiment. Despite the effects of Rht‐D1 alleles in Mercia on stress tolerance, the inconsistency of the effects over background and locus led to the conclusion that semidwarfing with GA‐insensitivity did not necessarily increase sensitivity to stress at booting and flowering. In comparison with effects of semidwarfing alleles, responses to heat stress are much more dramatically affected by water availability and the precise growth stage at which the stress is experienced by the plants.     

The potential of genomic‐assisted breeding to improve Fusarium head blight resistance in winter durum wheat

Durum wheat is the most important tetraploid wheat mainly used for semolina and pasta production, but is notorious for its high susceptibility to Fusarium head blight (FHB). Our objectives were to identify and characterize quantitative trait loci (QTL) in winter durum and to evaluate the potential of genomic approaches for the improvement of FHB resistance. Here, we employed an international panel of 170 winter and 14 spring durum lines, phenotyped for Fusarium culmorum resistance at five environments. Heading date, plant height and mean FHB severity showed significant genotypic variation with high heritabilities and FHB resistance was negatively correlated with both heading date and plant height. The dwarfing gene Rht‐B1 significantly affected FHB resistance and the genome‐wide association scan identified eight additional QTL affecting FHB resistance, explaining between 1% and 14% of the genotypic variation. A genome‐wide prediction approach yielded only a slightly improved predictive ability compared to marker‐assisted selection based on the four strongest QTL. In conclusion, FHB resistance in durum wheat is a highly quantitative trait and in breeding programmes may best be tackled by classical high‐throughput recurrent phenotypic selection that can be assisted by genomic prediction if marker profiles are available.     

Oligogenic control of resistance to soil‐borne viruses SBCMV and WSSMV in rye (Secale cereale L.)

Rye production in European growing areas is constrained by the soilborne cereal mosaic virus (SBCMV) and the wheat spindle streak mosaic virus (WSSMV). To date, no European rye cultivars are known to exhibit resistance against these viruses. In this study, we pursued a quantitative trait locus (QTL) mapping strategy to identify genomic regions for resistance to SBCMV and WSSMV in rye. Three populations, each comprising 100 lines segregating for resistance to SBCMV and/or WSSMV, were evaluated for disease response at two years in three locations in Germany where soils are naturally infested with SBCMV and WSSMV. In the combined analysis across environments, one QTL for SBCMV resistance on chromosome 5R explained 31.9% of the phenotypic variation in one of the populations. For WSSMV resistance, one QTL explaining up to 64.0% of the phenotypic variation was detected on chromosome 7R in each of the three populations. On the Triticeae homoeologous group 5, we found evidence for synteny of the major QTL for SBCMV resistance between the wheat and rye genomes.     

Breeding for salinity resistance in mulberry (<Emphasis Type="Italic">Morus</Emphasis> spp.)

Late maturity α-amylase (LMA) is a genetic defect that is fairly widely spread in bread wheat (Triticum aestivum L.) germplasm, and recently detected in durum cultivars, which can result in unacceptably high α-amylase activity (low falling number) in ripe grain. LMA has also been observed at unexpectedly high frequency and severity in synthetic hexaploid wheats derived from the interspecific hybridisation of Triticum durum (AABB) and Aegilops tauschii (DD). Since synthetic hexaploids represent an important new source of resistances/tolerances to a range of biotic and abiotic stresses for wheat breeders, there is a pressing need to understand the mechanisms involved in LMA in synthetics and develop strategies for avoiding its adverse effects on grain quality. The objectives of this study were to firstly, compare the LMA phenotype of synthetics that varied for plant height, secondly, to characterise the LMA phenotype in groups of synthetics derived from the same durum parents and finally to determine whether LMA in primary synthetics is associated with the QTL previously reported in conventional bread wheat. More than 250 synthetic hexaploids, a range of durum cultivars and a doubled haploid population derived from Worrakatta (non-LMA) × AUS29663 (high LMA synthetic) were phenotyped and genotyped with markers reported to be linked to LMA in conventional bread wheat and markers diagnostic for the semi-dwarfing gene, Rht1. More than 85% of synthetics were prone to LMA, approximately 60% ranked as very high. Genetic control of LMA in synthetic hexaploids appeared to involve QTL located on 7B, and to a lesser extent 3B, similar to bread wheats. However, the LMA phenotype of many synthetic hexaploids appeared to be more extreme than could be explained by comparisons with bread wheat even taking into account the apparent absence of Rht1 in most genotypes. Other mechanisms, possibly triggered by the interaction between the AABB and DD genomes cannot be excluded. The presence of wild type rht1 in most synthetic hexaploids and their extreme height is difficult to reconcile with the semi-dwarf, Rht1, stature of many of the durums used in the interspecific hybridisation process. Mechanisms that could explain this observation remain unclear.     

QTL mapping of adult‐plant resistance to stripe rust in a ‘Lumai 21 × Jingshuang 16’ wheat population

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a devastating fungal disease in common wheat (Triticum aestivum L.) worldwide. Chinese wheat cultivars ‘Lumai 21’ and ‘Jingshuang 16’ show moderate levels of adult‐plant resistance (APR) to stripe rust in the field, and they showed a mean maximum disease severity (MDS) ranging from 24 to 56.7% and 26 to 59%, respectively, across different environments. The aim of this study was to identify quantitative trait loci (QTL) for resistance to stripe rust in an F₃ population of 199 lines derived from ‘Lumai 21’ × ‘Jingshuang 16’. The F₃ lines were evaluated for MDS in Qingshui, Gansu province, and Chengdu, Sichuan province, in the 2009–2010 and 2010–2011 cropping seasons. Five QTL for APR were detected on chromosomes 2B (2 QTL), 2DS, 4DL and 5DS based on mean MDS in each environment and averaged values from all three environments. These QTL were designated QYr.caas‐2BS.2, QYr.caas‐2BL.2, QYr.caas‐2DS.2, QYr.caas‐4DL.2 and QYr.caas‐5DS, respectively. QYr.caas‐2DS.2 and QYr.caas‐5DS were detected in all three environments, explaining 2.3–18.2% and 5.1–18.0% of the phenotypic variance, respectively. In addition, QYr.caas‐2BS.2 and QYr.caas‐2BL.2 colocated with QTL for powdery mildew resistance reported in a previous study. These APR genes and their linked molecular markers are potentially useful for improving stripe rust and powdery mildew resistances in wheat breeding.     

Dissection of a major QTL for seed colour and fibre content in Brassica napus reveals colocalization with candidate genes for phenylpropanoid biosynthesis and flavonoid deposition

A major quantitative trait locus (QTL) influencing seed fibre and colour in Brassica napus was dissected by marker saturation in a doubled haploid (DH) population from the black‐seeded oilseed rape line ‘Express 617’ crossed with a yellow‐seeded B. napus line, ‘1012–98’. The marker at the peak of a sub‐QTL with a strong effect on both seed colour and acid detergent lignin content lay only 4 kb away from a Brassica (H+)‐ATPase gene orthologous to the transparent testa gene AHA10. Near the peak of a second sub‐QTL, we mapped a copy of the key phenylpropanoid biosynthesis gene cinnamyl alcohol dehydrogenase, while another key phenylpropanoid biosynthesis gene, cinnamoyl co‐a reductase 1, was found nearby. In a cross between ‘Express 617’ and another dark‐seeded parent, ‘V8’, Bna.CCR1 was localized in silico near the peak of a corresponding seed fibre QTL, whereas in this case Bna.CAD2/CAD3 lay nearby. Re‐sequencing of the two phenylpropanoid genes via next‐generation amplicon sequencing revealed intragenic rearrangements and functionally relevant allelic variation in the three parents.     

Wheat Rht‐B1 Dwarfs Exhibit Better Photosynthetic Response to Water Deficit at Seedling Stage Compared to the Wild Type

Wheat reduced height (Rht) genes encode modified DELLA proteins, which are gibberellin insensitive, accumulate under stress, restrain growth and affect plant stress response. The seedling reaction to soil water deficit regarding leaf gas exchange and chlorophyll fluorescence was compared in near‐isogenic lines carrying the alleles Rht‐B1a (tall), Rht‐B1b (semi‐dwarfing) and Rht‐B1c (dwarfing) and was related to leaf water content and anatomy. Under drought, Rht‐B1c line was characterized by less decreased CO₂ assimilation, delayed non‐stomatal limitation of photosynthesis and higher instantaneous water use efficiency. The functional state of its photosynthetic apparatus was better preserved as evidenced by the less decreased actual quantum yield (Φ_PSII) and potential maximum quantum yield (F_v/F_m) of PSII, and the less increased quantum yield of non‐regulated energy dissipation (Φ_NO). Rht‐B1b line also tended to perform better than Rht‐B1a, but differences were less pronounced. Although the leaves of both dwarf lines were smaller, thicker and more pubescent, their water content was not higher in comparison with the tall line. Nevertheless, in Rht‐B1c, leaf thickness was less decreased and mesophyll cells were less shrunk under drought. The more effective performance of the photosynthetic machinery of dwarf lines under water deficit could be explained by a combination of morpho‐anatomical and metabolic characteristics.     

Changes in Water Status,Membrane Stability and Antioxidant Capacity of Wheat Seedlings Carrying Different Rht‐B1 Dwarfing Alleles under Drought Stress

Water deficiency is a major constraint to wheat productivity in drought prone regions. The wheat DELLA‐encoding height‐reducing genes (Rht) are associated with significant increase in grain yield. However, the knowledge of their benefit in dry environments is insufficient. The objective of the study was to examine the effect of induced drought on leaf water content, level of oxidative stress, cell membrane stability, accumulation of osmoprotectants and activity of some antioxidant enzymes in wheat near‐isogenic lines carrying the alleles Rht‐B1b (semidwarfing) and Rht‐B1c (dwarfing) in comparison with the tall control Rht‐B1a. Six‐day‐long water deprivation was imposed at seedling stage. Plants carrying Rht‐B1c and, to a lesser extent, those carrying Rht‐B1b performed better under stress compared with Rht‐B1a in terms of more sustained membrane integrity, enhanced osmoregulation and better antioxidant defence. These differential responses could reflect pleiotropic effects of the Rht‐B1 gene associated with the accumulation of the mutant gene product, that is, altered DELLA proteins, or might be related to allelic variations at neighbouring loci carrying candidate genes for proteins with a major role in plant water regulations and stress adaptation. These findings might be of importance to breeders when introducing Rht‐B1 alleles into wheat cultivars designed to be grown in drought liable regions.     

1BL/1RS易位对小麦产量性状和白粉病抗性的影响及其QTL分析

用PH82-2/内乡188杂交后代240个F_5:6家系,按照α-lattice设计,分别种植在安阳、焦作和泰安,对产量和抗白粉病等性状进行了考察。利用SSR和蛋白标记对群体进行部分连锁作图,分析1BL/1RS易位对产量及其相关性状的遗传效应。结果表明,1BL/1RS易位系对产量、穗数/m²和抽穗期的影响不显著;易位系的千     

Dissecting gene × environmental effects on wheat yields via QTL and physiological analysis

Crops frequently display genotype × environment interaction for yield and end-use quality in response to different environments, particularly when stresses such as water limitation and temperature are components of the interaction. Plant breeders usually exploit this variation via phenotypic selection to develop varieties with both general and specific adaptation. However the individual genes and physiological processes underlying the basis of general and specific adaptation have rarely been elucidated. We are combining large-scale QTL analysis of several doubled haploid populations of wheat, grown over different environments and seasons, with detailed physiological analysis, to dissect the genes and mechanisms responsible for yield and yield × environment variation in adapted European winter germplasm. Analysis of populations grown under irrigated and non-irrigated conditions on drought-prone soils has revealed individual genes showing stable and differential expression over environments, and the analysis has also identified physiological traits that contribute to differential yield performance. Genes on the homoeologous group 2 chromosomes were associated with flag leaf senescence (stay-green) variation and were the most significant in drought interactions. Variation for stem soluble carbohydrate reserves was associated with the 1RS arm of the 1BL/1RS translocated chromosome, and was positively correlated with yield under both irrigated and non-irrigated conditions, and thus general adaptability. Separate analyses of populations grown over three seasons in England, Scotland, France and Germany revealed QTL for yield performance showing both general and specific effects. A stable QTL on chromosome 6A, consistent in different populations, showed significant effects over seasons and environments, whilst other QTL were specific to season and/or environments.     

Identification and validation of an over‐dominant QTL controlling soybean seed weight using populations derived from Glycine max × Glycine soja

Heterosis, or hybrid vigour, has been used to improve seed yield in several important crops for decades and it has potential applications in soybean. The discovery of over‐dominant quantitative trait loci (QTL) underlying yield‐related traits, such as seed weight, will facilitate hybrid soybean breeding via marker‐assisted selection. In this study, F₂ and F_2 : 3 populations derived from the crosses of ‘Jidou 12’ (Glycine max) × ‘ZYD2738’ (Glycine soja) and ‘Jidou 9’ (G. max) × ‘ZYD2738’ were used to identify over‐dominant QTL associated with seed weight. A total of seven QTL were identified. Among them, qSWT_13_1, mapped on chromosome 13 and linked with Satt114, showed an over‐dominant effect in two populations for two successive generations. This over‐dominant effect was further examined by six subpopulations derived from ‘Jidou12’ × ‘ZYD2738’. The seed weight for heterozygous individuals was 1.1‐ to 1.6‐fold higher than that of homozygous individuals among the six validation populations examined in different locations and years. Therefore, qSWT_13_1 may be a useful locus to improve the yield of hybrid soybean and to understand the molecular mechanism of heterosis in soybean.     

An STS marker distinguishing the rye-derived powdery mildew resistance alleles at the Pm8/Pm17 locus of common wheat

A sequence‐tagged site marker has been developed from restriction fragment length polymorphism marker probe IAG95 for the rye‐derived powdery mildew resistance Pm8/Pm17 locus of common wheat. This polymerase chain reaction marker enables the amplification of DNA fragments with different sizes from T1AL.1RS and T1BL.1RS wheat‐rye translocation cultivars with chromatin from ‘Insave’ and ‘Petkus’ rye, respectively, and therefore will be very useful in distinguishing Pm8‐carrying cultivars from Pm17‐carrying cultivars. Results obtained with that marker were compared with resistance tests performed on detached primary leaves of 29 wheat lines from two populations derived from doubled haploid production. The molecular assay corresponded well with the resistance tests in all the lines, and therefore will be helpful for the identification of Pm17 in lines in which other Pm genes or quantitative trait loci are present.     

Resistance to Fusarium crown rot in wheat and barley: a review

Fusarium crown rot (FCR) is becoming a major disease in many parts of the cereal‐growing regions worldwide. Significant QTL conferring FCR resistance have been reported on 13 of the 21 possible hexaploid wheat chromosomes in wheat and on three of the seven chromosomes in barley. Available results show that host resistance to FCR is not pathogen species‐specific, that resistance QTL have strong additive effect and that both plant height and growth rate affect FCR severity. Further, different loci seem to be responsible for resistances to FCR and Fusarium head blight although both diseases can be caused by the same Fusarium pathogens. Although marker‐assisted selection for FCR resistance has been initiated, the available markers are all derived from QTL mapping, which provides only limited resolution. Further work has to be conducted in developing diagnostic markers before significant progress can be made in deploying marker‐assisted selection as a routine tool to accelerate and improve FCR in breeding programmes.     

Identification of QTL controlling high levels of partial resistance to Fusarium solani f. sp. pisi in pea

Fusarium root rot is a common biotic restraint on pea yields, and genetic resistance is the most feasible method for improving pea production. This study was conducted to discover quantitative trait loci (QTL) controlling genetic partial resistance to Fusarium root rot caused by Fusarium solani (Mart.) Sacc. f.sp. pisi (F.R. Jones) W.C. Snyder & H.N. Hans (Fsp). A RIL population was screened in a Fusarium root rot field disease nursery for 3 years. Composite interval mapping was employed for QTL detection using the means of disease severity from three growing seasons. Five QTL were identified, including one QTL identified in all three years. The multiyear QTL Fsp‐Ps2.1 contributed to a significant portion of the phenotypic variance (22.1–72.2%), while a second QTL, Fsp‐Ps6.1, contributed 17.3% of the phenotypic variance. The other single growing season QTL are of additional interest as they colocate with previously reported pea–Fusarium root rot resistance QTL. QTL Fsp‐Ps2.1, Fsp‐Ps3.1, Fsp‐4.1 and Fsp‐Ps7.1 are flanked by codominant SSRs and may be useful in marker‐assisted breeding of pea for high levels of partial resistance to Fsp.     

Development of molecular markers for crown rot resistance in wheat: mapping of QTLs for seedling resistance in a '2-49' × 'Janz' population

Crown rot, caused by Fusarium pseudograminearum, is an important disease of wheat in Australia and elsewhere. In order to identify molecular markers associated with partial seedling resistance to this disease, bulked segregant analysis and quantitative trait loci (QTL) mapping approaches were undertaken using a population of 145 doubled haploid lines constructed from ‘2‐49’ (partially resistant) × ‘Janz’ (susceptible) parents. Phenotypic data indicated that the trait is quantitatively inherited. The largest QTLs were located on chromosomes 1D and 1A, and explained 21% and 9% of the phenotypic variance, respectively. Using the best markers associated with five QTLs identified by composite interval mapping, the combined effect of the QTLs explained 40.6% of the phenotypic variance. All resistance alleles were inherited from ‘2‐49’ with the exception of a QTL on 2B, which was inherited from ‘Janz’. A minor QTL on 4B was loosely linked (19.8 cM) to the Rht1 locus in repulsion. None of the QTLs identified in this study were located in the same region as resistance QTLs identified in other populations segregating for Fusarium head blight, caused by Fusarium graminearum.     

Quantitative trait loci (QTL) mapping of silique length and petal colour in Brassica rapa

Recombinant inbred lines (RILs) derived from a cross between Brassica rapa L. cv. ‘Sampad’, and an inbred line 3‐0026.027 was used to map the loci controlling silique length and petal colour. The RILs were evaluated under four environments. Variation for silique length in the RILs ranged from normal, such as ‘Sampad’, to short silique, such as 3‐0026.027. Three QTL, SLA3, SLA5 and SLA7, were detected on the linkage groups A3, A5 and A7, respectively. These QTL explained 36.0 to 42.3% total phenotypic variance in the individual environments and collectively 32.5% phenotypic variance. No additive × additive epistatic interaction was detected between the three QTL. Moreover, no QTL × environment interaction was detected in any of the four environments. The number of loci for silique length detected based on QTL mapping agrees well with the results from segregation analysis of the RILs. In case of petal colour, a single locus governing this trait was detected on the linkage group A2.