Exotic Line Research Articles

Molecular Genetic Diversity of Local and Exotic Durum Wheat Genotypes and Their Combining Ability for Agronomic Traits under Water Deficit and Well-Watered Conditions.

Water deficit poses significant environmental stress that adversely affects the growth and productivity of durum wheat. Moreover, projections of climate change suggest an increase in the frequency and severity of droughts, particularly in arid regions. Consequently, there is an urgent need to develop drought-tolerant and high-yielding genotypes to ensure sustained production and global food security in response to population growth. This study aimed to explore the genetic diversity among local and exotic durum wheat genotypes using simple sequence repeat (SSR) markers and, additionally, to explore the combining ability and agronomic performance of assessed durum wheat genotypes and their 28 F1 crosses under normal and drought stress conditions. The investigated SSRs highlighted and confirmed the high genetic variation among the evaluated parental durum wheat genotypes. These diverse eight parental genotypes were consequently used to develop 28 F1s through a diallel mating design. The parental durum genotypes and their developed 28 F1s were assessed under normal and drought stress conditions. The evaluated genotypes were analyzed for their general and specific combining abilities as well as heterosis for agronomic traits under both conditions. The local cultivar Bani-Suef-7 (P8) is maintained as an effective combiner for developing shortened genotypes and improving earliness. Moreover, the local cultivars Bani-Suef-5 (P7) and Bani-Suef-7 (P8) along with the exotic line W1520 (P6) demonstrated excellent general combining ability for improving grain yield and its components under drought stress conditions. Furthermore, valuable specific hybrid combinations, W988 × W994 (P1 × P2), W996 × W1518 (P3 × P5), W1011 × W1520 (P4 × P6), and Bani-Suef-5 × Bani-Suef-7 (P7 × P8), were identified for grain yield and its components under drought stress conditions. The assessed 36 genotypes were grouped according to tolerance indices into five clusters varying from highly drought-sensitive genotypes (group E) to highly drought-tolerant (group A). The genotypes in cluster A (two crosses) followed by thirteen crosses in cluster B displayed higher drought tolerance compared to the other crosses and their parental genotypes. Subsequently, these hybrids could be considered valuable candidates in future durum wheat breeding programs to develop desired segregants under water-deficit conditions. Strong positive relationships were observed between grain yield and number of grains per spike, plant height, and 1000-grain weight under water-deficit conditions. These results highlight the significance of these traits for indirect selection under drought stress conditions, particularly in the early stages of breeding, owing to their convenient measurability.

Evaluation of Bread Wheat Genotypes for Water Stress Tolerance Using Agronomic Traits

Water stress is one of the major environmental constraints on wheat grain yield worldwide. One way to overcome this limitation is to evolve genetically stress-tolerant wheat genotypes that produce sustainable grain yields in water-scarce conditions. A field experiment was carried out to investigate the genetic diversity of 34 advanced wheat genotypes (<i>Triticum aestivum</i> L.) and two commercial check varieties (Khirman and TD-1) for grain yield and yield-associated agronomic traits in moisture stress (MS) and well-watered (WW) conditions. Plants were grown in residual moisture in rice fallow land in rainfed conditions without supplementary irrigation, i.e., MS conditions, while two rounds of irrigations were applied for the WW control conditions. Analysis of variance indicated a highly significant (<i>p</i> < 0.05) variation among genotypes for all the observed agronomic traits in MS and WW conditions. In the MS group, the exotic line IBWSN-1010, mutant line MASR-64, and doubled haploid line DH-12/7 produced the highest grain yield compared to all the contesting wheat genotypes, including check varieties. Grain yield per plot was positively correlated (<i>r</i> = 0.93) with biological yield per plot in MS conditions. Principal component analysis showed total variations of 21.9%, 20.4%, and 10.1% explained by PC-1, PC-2, and PC-3 in MS, and 22.9%, 14.8%, and 12.1% for PC-1, PC-2, and PC-3 in WW conditions. Our study provides valid information for the selection of newly evolved wheat genotypes and will be useful in future breeding programs.

The AdS𝜃2/CFT1 correspondence and noncommutative geometry II: Noncommutative quantum black holes

In this paper, we present the construction of noncommutative [Formula: see text] black hole and its four-dimensional Yang–Mills IKKT-type matrix model which includes two competing Myers term one responsible for the condensation of pure [Formula: see text] and the other one responsible for the condensation of the dilaton field. It is argued that the phase diagram of this matrix model features three phases: (1) a gravitational phase ([Formula: see text] black hole), (2) a geometric phase ([Formula: see text] background) and (3) a Yang–Mills phase. The Hawking process is therefore seen as an exotic line of discontinuous transitions between the gravitational and geometrical phases. Alternatively, a noncommutative nonlinear sigma model describing the transition of the dilaton field between the gravitational and geometrical phases is also constructed.

Heterosis and Combining Ability for Fruit Yield, Sweetness, β-Carotene, Ascorbic Acid, Firmness and Fusarium Wilt Resistance in Muskmelon (Cucumis melo L.) Involving Genetic Male Sterile Lines

Ten genetically diverse inbred lines, including two genic male sterile lines, of muskmelon (Cucumis melo L.) were crossed in a half-diallel to generate 45 F1 hybrids. These hybrids, along with the parental lines and commercial check, were evaluated for their fruit yield, level of phytochemicals and Fusarium wilt resistance. Both additive and non-additive genetic variances were important in governing the expression of all of the traits; however, the additive gene action for the fruit weight (g), flesh thickness (cm), rind thickness (mm), firmness (lb inch−2), β-carotene content (mg/100 g), non-additive variance for fruit yield (t ha−1), fruit number, total soluble solids (TSS, °Brix), ascorbic acid (mg/100 g) and reaction to Fusarium wilt were comparatively more important. The parental line MM-625 was the best general combiner for fruit yield, rind thickness and β-carotene content (mg/100 g). The exotic line Riogold was the best combiner for flesh thickness and firmness. The netted inbred line MM-610 was the best general combiner for fruit weight, ascorbic acid and reaction to Fusarium wilt. The inbred lines KP4HM-15 and MM-916 were the best general combiners for the number of fruits per vine and TSS. The best cross-combinations for fruit yield ha−1 and TSS were MS-1×M-610 and Kajri×MM-904, respectively. The hybrids KP4HM-15×MM Sel-103 and KP4HM-15×MM-1831 recorded the highest standard heterosis for fruit yield and TSS. The landrace-derived inbred lines Kajri, MM Sel-103 and KP4HM-15 produced moderate-to-highly FW-resistant hybrids. Out of the 121 SSR markers applied, 70 exhibited parental polymorphism. The markers DM0561, CMAAAGN14, TJ147, CMMS35_3, CMAGN45 and DE1337 identified specific/unique alleles in certain parental genotypes. Thus, the findings of this study revealed that the novel inbred lines can effectively be combined to generate heterotic F1 hybrids for yield and other traits, such as rind and flesh thickness, TSS, β-carotene content and firmness. Furthermore, SSR markers can potentially be utilized to confirm the genetic diversity among the parental lines, and for the DNA fingerprinting of F1 hybrids.

Mapping and linkage analysis of epistatic QTLs for gynoecious trait (F) in cucumber (Cucumis sativus L.)

ABSTRACT The QTL mapping for gynoecy in cucmber (Cucumis sativus L.)was carried out by using backcross populations (BC1F2 & BC1F3) of a cross using two inbred lines; one monoecious with multiple (≥ 5) lateral branching habit cv. Pusa Uday (Indian slicing type) and gynoecious exotic line Gy14 (American pickling type) with few lateral branches (1–2). QTL detection was performed by employing QTL Ici mapping software (version 4.1) of the two mapping populations. We detected seven gynoecious QTLs in two genomic regions (chromosome 5 and 6), on which three significant QTLs (qGyn 5.1, qGyn 6.5 and qGyn 6.6) had higher LOD score (10.5, 26.2, and 24.5) and phenotypic variance (5.9, 14.5 and 14.5%) in BC1F2 population. However, two significant QTLs (qGyn 5.1 and qGyn 6.1) accounted for gynoecism which could explain 22.90 and 12.88% of the phenotypic variation with the LOD score of 15.86 and 11.82 in linkage group 5 and 6, respectively in BC1F3 population. Out of 82 simple sequence repeats (SSR) markers, three (SSR00233, SSR15516 and SSR13251) was found tightly linked and flanked to gynoecious trait QTLs (qGyn6.5 and qGyn6.6) in BC1F2 population at <1.5 cM, which could be used for marker-assisted selection (MAS) in cucumber improvement programmes. In order to increase the productivity of Indian cucumber, the introgressed Indian gynoecious cucumber lines derived from an exotic genetic background using MAS may be directly used as a variety or parent of hybrid.

Genetic diversity in exotic oat germplasm &amp; resistance against barley yellow dwarf virus

Oat (Avena sativa L.) is an important fodder crop of Pakistan, though with low productivity. The present study was conducted to evaluate the performance and genetic diversity of exotic oat germplasm, with emphasis on cereal yellow dwarf virus resistance. A total of 16 exotic line (introduced from Aarhus University Denmark) and 1 local line (provided by The University of Agriculture Peshawar), were grown during the season 2017–18 in Completely Randomized Block Design with three replications across two locations of Khyber Pakhtunkhwa i.e., Peshawar and Kohat. Field testing enabled to collect the data on BYDV incidence, BYDV severity, aphid infestation, plant height, leaf area, panicle length, panicle weight, spikelets per panicle, 1000 grain weight (g), grain yield (g), biological yield (g) and harvest index (%). Prevalence of BYDV was variable across location and over time. Six weeks data showed high disease pressure at Peshawar (85%), with SA-O-01 genotype having AUDPC value of 95%. Almost all the varieties showed less tolerance towards the Aphids attack. Line SA-O-15 showed the maximum 1000 grain weight (42.6 g) at Kohat, while SA-O-4 showed the maximum 1000 grain weight (60.7 g) at Peshawar. Line SA-O-05 (3634 g per (0.9 m2) plot) gave the maximum biological yield at Kohat station, while Line SA-O-01 gave the maximum biological yield (2517 g) at Peshawar. Mean grain yield for Kohat was recorded 0.155 g per (0.9 m2) plot while for Peshawar it was 0.231 g per (0.9 m2) plot. At Kohat line SA-O-10 produced the maximum grain yield (0.229 g), while line SA-O-12 produced the maximum grain yield at Peshawar (0.288 g). Molecular genotyping with a set of 4 RAPD primers revealed substantial diversity among17 oat lines. A total of 23 loci were amplified showing a high level of variations and polymorphism among the proposed lines. The maximum number of loci was recorded for GLA-04 (8), while the minimum number of loci was recorded for GLD-18 (4). Among the tested RAPD primers the maximum gene diversity (0.529) was recorded for loci GLA-03B230, GLA-04B130, GLA-04B300, GLB-05B150 and GLA-18B100 while the minimum (0.118) genetic diversity was recorded for loci GLA-03B600, GLB-05B330 and GLA-18B500. A clear divergence was found between most of the exotic oat lines. The observed genetic diversity in exotic oat germplasm and its resistance towards Barley Yellow Dwarf virus could be useful for oat genetic improvement and broadening the genetic background of cultivated oat germplasm.

Nonlinear Mode Coupling and One-to-One Internal Resonances in a Monolayer WS2 Nanoresonator.

Nanomechanical resonators make exquisite force sensors due to their small footprint, low dissipation, and high frequencies. Because the lowest resolvable force is limited by ambient thermal noise, resonators are either operated at cryogenic temperatures or coupled to a high-finesse optical or microwave cavity to reach sub aN Hz-1/2 sensitivity. Here, we show that operating a monolayer WS2 nanoresonator in the strongly nonlinear regime can lead to comparable force sensitivities at room temperature. Cavity interferometry was used to transduce the nonlinear response of the nanoresonator, which was characterized by multiple pairs of 1:1 internal resonance. Some of the modes exhibited exotic line shapes due to the appearance of Hopf bifurcations, where the bifurcation frequency varied linearly with the driving force and forms the basis of the advanced sensing modality. The modality is less sensitive to the measurement bandwidth, limited only by the intrinsic frequency fluctuations, and therefore, advantageous in the detection of weak incoherent forces.

Induction of Salt Tolerance in Tomato Through Seed Priming

A pot experiment was conducted in the Net House of “Field Laboratory of Plant Stress Management” in the Horticulture farm of Sher-e-Bangla Agricultural University, Dhaka, during the period from October 2016 to March 2017. The two factors experiment was laid out in Complete Randomized Design with five replications. Factor A is three tomato varieties viz. V₁= Exotic line 1 (Korean), V₂= Exotic line 2 (Taiwan) and V₃= BARI tomato 14 and factor B is seed priming treatment viz. P₀= No priming (Control), P₁= Hydropriming (distilled water), P₂= NaCl priming (50 mM) and P₃= KNO₃ priming (200 mM). The total treatment combinations were (4×3) 12 and 8 dS/m fixed salinity maintained for all the pots. The experimental results exhibited that seed priming treatment significantly affected growth, yield and quality parameters of tomato. The highest plant height (137.10 cm), number of fruits per plant (40.92) and fruit yield per plant (585.00 g) were found from V₁ under 8 dS/m salinity level. In case of seed priming, the highest plant height (150.10 cm), number of fruits per plant (48.11) and fruit yield per plant (755.80 g) were recorded from P₂ mostly at 8 dS/m salinity level. Regarding the combined effect, the highest plant height (187.00 cm), number of fruits per plant (55.00) and fruit yield per plant (829.30 g) were found from V₁P₂ under 8 dS/m salinity level. So, Exotic line 1 with NaCl priming (50mM) showed better performance for growth, yield and quality of tomato under saline condition.

Component traits influencing seed yield in recombinant inbred lines of lentil (Lens culinaris Medik.)

One hundred and thirty five RILs (Recombinant Inbred Lines) developed from a cross between an indigenous and exotic line of lentil (Lens culinarisMedik.)were evaluated for seed yield and component traits during rabi 2012-13 and 2013-14. Pooled analysis of variance revealed significant differences among the RILsfor all the traits studied. This suggested that there was ample scope for selection of promising RILs for yield improvement in lentil. Phenotypic and genotypic coefficients of variation were high for pods per plant(32.49% and 26.75%) followed by biological yield per plot(24.38% and 21.28%). Genetic advance was highest for 100-seed weight(47.75%)followed by pods per plant(45.39%). Estimation of phenotypic correlation coefficients indicated that seed yield per plot expressed highly significant and positive correlation with biological yield per plot(0.634), harvest index(0.300) and seeds per pod(0.156). Path coefficient analysis revealed that the traits; biological yield per plot , harvest index, number of pods per plant, days to 50% flowering, days to maturity , plant height and primary branches per plant had positive direct effect on seed yield per plot. The selection of these traits would be helpful for further yield improvement in lentil.

Comparison of milk production and milk composition for an exotic and a local synthetic rabbit lines.

Aim:Basic objective of this research was to compare two rabbit lines: V-line (exotic line), Alexandria (local synthetic line) for yield and composition of milk product and their effect on productive performance of rabbits.Materials and Methods:The experiment was conducted on 80 does and their kits. Milk yield (MY) of each doe and milk composition (MC) were recorded at 3rd week of lactation.Results:The results of MY showed insignificant difference between V-line and Alexandria line. While the results of MC indicated significant differences in milk protein and fat between the two lines. The protein electrophoresis was used for assaying variation in milk proteins between the two lines. The banding protein patterns showed seven protein bands for Alexandria line and six bands for V line. The results demonstrated one specific protein marker at 48 KDa (κ-casein) in Alexandria doe’s milk. Moreover, the results of individual body weight at weaning age indicated that Alexandria rabbits had significantly higher body weight compared with V-line rabbits (845.33 g, 664.05 g, respectively). Alexandria line had significantly lower mortality rate compared with V-line (1.5%, 2.7%, respectively).Conclusion:The differences which obtained in Alexandria line milk may play an important role in the productive performance of rabbits.

English

Phylogenetic relationship and polymorphism was detected in 10 cowpea lines comprising of leaf, flower and stem mutants, their putative parents and an exotic accession using 10 random amplified polymorphic DNAs (RAPDs) and three primer combinations of amplified fragment length polymorphism (AFLP) markers. These mutants were earlier obtained through the probable activities of transposable elements. The RAPD and AFLP markers revealed a genetic diversity of 47 and 31%, respectively, within the cowpea lines used. &nbsp;Genetic distance ranged from 0.05 to 0.30 based on AFLP markers, while it ranged between 0.13 and 0.44 for RAPD markers. Cluster analysis indicated that there are differences in RAPD markers between the various mutants and it grouped an exotic genotype separately. OPC-14 primer had the highest discriminatory capacity (11 polymorphic fragments). The AFLP analysis was able to group two of the flower mutants, leaf mutants and wild types separately. A combined analysis of the two markers gave a similar grouping as was obtained from the AFLP analysis. AFLP was more discriminatory in grouping the plant samples and the exotic line was distinguished based on both markers. Useful heterotic prediction can be done based on the genetic distance between the mutants and their parents. This will further broaden the genetic base of cowpea and enhance the use of these mutants which have some evolutionary significance. In addition, unique allele RAPD_OPC15-500bp can be harnessed in genetic identification of reduced petal mutant. This study further corroborates the discriminatory power of AFLP over RAPDs. Key words: Vigna unguiculata, amplified fragment length polymorphism (AFLP), randomly amplified polymorphic DNA (RAPD), mutants, transposable elements.

Genomewide Predictions for Backcrossing a Quantitative Trait from an Exotic to an Adapted Line

Phenotypic backcrossing for a quantitative trait is generally ineffective. An alternative approach is to use genomewide predictions to identify which plants should be crossed to the recurrent parent to form each successive backcross generation. My objective was to assess the amount of genetic gain achieved from the use of genomewide predictions during backcrossing for a quantitative trait. Simulation experiments were conducted with an adapted line as the recurrent parent and an exotic line as the donor parent. Compared with the expected allele frequencies in the absence of selection, genomewide selection during backcrossing increased the frequency of favorable alleles from the donor parent and slightly decreased the frequency of favorable alleles from the recurrent parent. The selection response (R), expressed as a standardized deviation from the performance of the recurrent parent, ranged from −1.44 to 1.76. Unless the number of QTL was large and the donor parent was very poor, the R values were positive as long as an F2 training population was used and all of the markers were included in the genomewide predictions. Lines derived from the BC6 to BC8 generation typically had &lt;4 favorable alleles introgressed from the donor parent. Notably, the improved lines carried different subsets of favorable alleles from the donor parent. The approach described herein is most appropriate when a breeder aims to largely retain the genetic background and characteristics of the recurrent parent, with only incremental improvements that enhance the recurrent parent for quantitative traits.

Genome-Wide Mapping of Spike-Related and Agronomic Traits in a Common Wheat Population Derived from a Supernumerary Spikelet Parent and an Elite Parent.

In wheat, exotic genotypes harbor a broad range of spike-related traits, and can be used as a source of new genes for germplasm enhancement in wheat breeding programs. In the present study, a population of 163 recombinant inbred lines was derived from a cross between an elite line (WCB414) and an exotic line (WCB617) with branched spike (supernumerary spikelet; SS) head morphology. The population was evaluated over four to six environments to identify quantitative trait loci (QTL) associated with nine spike-related traits and 10 agronomic traits. A genetic map consisting of 939 diversity arrays technology (DArT) markers was constructed. Composite interval mapping identified a total of 143 QTL located on 17 different wheat chromosomes and included 33 consistent and definitive QTL. The amount of phenotype variation explained (PVE) by individual QTL ranged from 0.61 to 91.8%. One major QTL for glume pubescence was located in a QTL-rich region on the short arm of chromosome 1A, where loci for other traits such as for kernels per spike (KS) and spike length (SL) were also identified. Similarly, a cluster of QTL associated with yield-related, agronomic and spike-related traits contributing up to 40.3% of PVE was found on the short arm of chromosome 2D, in the vicinity of a major QTL for SS-related traits. Consistent and major QTL identified in the present study may be useful in marker-assisted breeding programs to facilitate transfer of desirable alleles into other germplasm. Desirable QTL alleles were also contributed by the exotic line, suggesting the possibility of enriching the breeding germplasm with alleles from SS genotypes.

New QTL alleles for quality-related traits in spring wheat revealed by RIL population derived from supernumerary × non-supernumerary spikelet genotypes.

A population developed from an exotic line with supernumerary spikelets was genetically dissected for eight quality traits, discovering new genes/alleles with potential use in wheat breeding programs. Identifying new QTLs and alleles in exotic germplasm is paramount for further improvement of quality traits in wheat. In the present study, an RIL population developed from a cross of an elite wheat line (WCB414) and an exotic genotype with supernumerary spikelets (SS) was used to identify QTLs and new alleles for eight quality traits. Composite interval mapping for 1,000 kernels weight (TKW), kernel volume weight (KVW), grain protein content (GPC), percent of flour extraction (FE) and four mixograph-related traits identified a total of 69 QTLs including 19 stable QTLs. These QTLs were located on 18 different chromosomes (except 4D, 5D, and 6D). Thirteen of these QTLs explained more than 15% of phenotypic variation (PV) and were considered as major QTLs. In this study, we identified 11 QTLs for TKW (R (2) = 7.2-17.1 %), 10 for KVW (R (2) = 6.7-22.5%), 11 for GPC (R (2) = 4.7-16.9%), 6 for FE (R (2) = 4.8-19%) and 31 for mixograph-related traits (R (2) = 3.2-41.2%). In this population, several previously identified QTLs for SS, nine spike-related and ten agronomic traits were co-located with the quality QTLs, suggesting pleiotropic effects or close linkage among loci. The traits GPC and mixogram-related traits were positively correlated with SS. Indeed, several loci for quality traits were co-located with QTL for SS. The exotic parent contributed positive alleles that increased PV of the traits at 56% of loci demonstrating the suitability of germplasm with SS to improve quality traits in wheat.

Multi-locational evaluation of Linseed (Linum usitatissimum L.) germplasm under rainfed ecology

Field experiments were conducted at three locations in augmented design during the winter season of 2008 allowed for the assessment of broad adaptation to dry and warm growing conditions of 100 linseed (Linum usitatissimum L.) accessions. Perusal of resultsrevealed that there exists sufficient genetic variability for seed yield in the studied linseed accessions. Sagar was adjudged best among the locationsfor harvesting a good yield. EC 704, an exotic line recorded highest seed yield at Sagar and Latur whereas, EC 1066, EC 1534 and EC 1466 recorded higher seed yield than the best check at all the three experimental sites showing a sign of wide adaptation. Such an approach to make efficient use of germplasm collections remains important even today. This contribution summarizesthat genotypes EC 704, EC 1066, EC 1534 and EC 1466 having stable yield potential may be exploited in the linseed breeding programme to combat global climate change.

Evaluation of garlic ecotypes for allicin and other allyl thiosulphinates

An aqueous extraction method coupled with ultra performance liquid chromatography with photo diode array detection was optimised and validated for screening of 93 garlic ecotypes for allicin and other allyl thiosulphinate contents. Variability in allicin, allyl methyl thiosulphinate and allyl trans-1-propenyl thiosulphinate was observed both on fresh and dry weight basis. Bulb to bulb variation for allicin levels was less in clonal selections followed by commercial varieties, exotic line and landraces, respectively. Five ecotypes on fresh weight basis and all the ecotypes on dry weight basis had allicin contents more than the recommended pharmacological values (⩾4.5mgg−1). Cluster analysis and principal component analysis results revealed that geographical origin, breeding status and colour did not play any role in ecotype clustering. This study is useful as a base for selection of garlic ecotypes as a dependable raw material source for pharmaceutical and food processing industries.

Improving Grain Yield and Yield Components of Temperate Maize Using Tropical Germplasm

The objectives of this study were: (1) to determine general combining ability (GCA) of 25 inbred lines selected from CIMMYT populations, specific combining ability (SCA), heterotic specific-group combining ability (HSPGCA) of testcrosses from these 25 lines, using four testers; (2) to determine optimum number of testers for evaluating a large number of exotic lines. The 25 exotic lines were crossed with four elite local maize inbred lines (a line × tester design). A randomized complete-block design with three replications was used at two locations. Data on grain yield and five yield-component traits were recorded. Combining ability analysis showed 8 exotic lines to be genetically similar to the testers and could be assigned to the two current maize heterotic groups. Correlation analysis indicated that one tester had correctly selected the top best lines from a large number of exotic lines. However, when line × location interaction is significant, exotic line performance should be evaluated at multiple loc...

A New Maize Heterotic Pattern between Temperate and Tropical Germplasms

New heterotic groups are needed for increasing genetic diversity and productivity in maize (Zea mays L.). A study was conducted with the following objectives: (i) to determine if exotic tropical maize germplasm (TRMG) can increase diversity of Chinese maize germplasm for grain yield and five yield component traits (YCTs), namely, ear length (EL), ear diameter (ED), number of kernel rows per ear (RE), number of kernels per row (KR), and 1000‐kernel weight (TKW), and (ii) to estimate general combining ability (GCA) and specific combining ability (SCA) effects to identify a possible new heterotic pattern. Twenty‐five temperate maize germplasm (TEMG) from both China and the United States were crossed with four TRMG from the International Maize and Wheat Improvement Center (CIMMYT). The 100 testcrosses were evaluated in field trials for grain yield and five YCTs at three locations in Yunnan, China. Tropical lines YML146 and YML145 showed, in crosses with most of the TEMG, significant positive SCA effects for grain yield and most of the YCTs, indicating that these lines had a different genetic base from that of TEMG and could increase genetic diversity of Chinese maize germplasm. The GCA effects were more important and reliable than SCA effects for heterotic pattern classification. Exotic line YML146 (derived from Suwan1) was identified as a new heterotic group, different from Reid, Lancaster, Tangsipingtou (TSPT), and Luda Red Cob (LDRC). A new heterotic pattern of temperate × Suwan1 was postulated, which could be as important as the widely accepted flint × dent heterotic pattern.

Geometry in Transition: A Model of Emergent Geometry

We study a three matrix model with global SO(3) symmetry containing at most quartic powers of the matrices. We find an exotic line of discontinuous transitions with a jump in the entropy, characteristic of a 1st order transition, yet with divergent critical fluctuations and a divergent specific heat with critical exponent alpha=1/2. The low temperature phase is a geometrical one with gauge fields fluctuating on a round sphere. As the temperature increased the sphere evaporates in a transition to a pure matrix phase with no background geometrical structure. Both the geometry and gauge fields are determined dynamically. It is not difficult to invent higher dimensional models with essentially similar phenomenology. The model presents an appealing picture of a geometrical phase emerging as the system cools and suggests a scenario for the emergence of geometry in the early Universe.

Quantitative trait loci of frost tolerance and physiologically related trait in faba bean (Vicia faba L.)

In faba bean, field based winter-hardiness is a complex trait that is significantly correlated to frost tolerance. Frost tolerance could be used to indirectly select for faba bean winter-hardiness. The aim of this study was to identify putative QTL associated with frost tolerance and auxiliary traits and to quantify the efficiency of marker assisted selection. Thus, 101 recombinant inbred lines derived from the cross between two frost tolerant lines were tested for their hardened and unhardened frost tolerance and for their leaf fatty acid content in both treatments. Significant differences among the RIL were observed for all studied traits. For frost tolerance, five putative QTL were detected; three for unhardened frost tolerance that explained 40.7% (8.6% after cross-validation, CV) of its genotypic variance and two for hardened frost tolerance that explained 21.8% (1.0% after CV). For fatty acid content, three QTL were detected for oleic acid content in unhardened leaves that explained 62.9% (40.6% after CV) of its genotypic variance. This fatty acid was significantly correlated with unhardened frost tolerance. The unbiased genotypic variance explained enabled to draw realistic prospects of MAS for frost tolerance. In this study, combined MAS was more efficient than classical phenotypic selection and was expected to be higher on larger populations at early generations. Moreover, favourable alleles inherited from the exotic line BPL 4628 could be introgressed to European winter-hardy beans for further improvement.