Breakdown of resistance to sorghum midge, Stenodiplosis sorghicola

Sorghum midge (Stenodiplosis sorghicola Coquillett) is an important pest of grain sorghum worldwide. Several sources of resistance to sorghum midge have been identified in the world sorghum germplasm collection, of which some lines show a susceptible reaction in Kenya. Therefore, we studied the insect density damage relationships for a diverse array of midge-resistant and midge-susceptible sorghum genotypes, and variation in association of glume and grain characteristics with expression of resistance to sorghum midge. AF 28 and IS 8891 showed resistance to sorghum midge both in India and Kenya; DJ 6514 and ICSV 197, which are highly resistant to sorghum midge in India, showed a susceptible reaction at Alupe, Kenya. Sorghum midge damage in general was greater in Kenya than that observed in India at the same level of midge density suggesting that the breakdown of resistance in Kenya is due to factors other than insect density. Glume length, glume breadth, and glume area were positively associated with susceptibility to sorghum midge at both locations. However, under natural infestation, the correlation coefficients were stronger in India than in Kenya. Grain mass at 3 and 6 days after anthesis was positively associated with susceptibility to midge in India, but did not show any association with midge damage in Kenya. Grain growth rate between 3 and 6 days after anthesis was more strongly correlated with susceptibility to midge in Kenya than in India. Variation in the reaction of sorghum genotypes across locations may be partly due to the influence of environment on association between glume and grain characteristics with susceptibility to sorghum midge, in addition to the possible differences in midge populations in different geographical regions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Response to Selection for Resistance to Macrophomina and Xanthomonas and its Association with Seed Colour in Cowpea*

In cowpea, black seeded types are supposedly resistant to Macrophomina. A study was undertaken to verify the association of seed colour with resistance to Macrophomina and Xanthomonas and to examine the response over three cycles of selection for such resistance along with seed yield, determinate habit and synchronous flowering in five black-and three white-seeded cowpea varieties. Selection was done between and within progenies under heavy natural incidence of both pathogens supplemented by artificial inoculation of Macrophomina using the toothpick method at flower primordial stage. Among 414 single plant progenies in the first cycle all 193 white-seeded progenies from three different varieties were highly susceptible to both pathogens, with considerable variation among the black-seeded ones. All the black- and white-seeded progenies derived from the same variety‘Floricream’were highly susceptible. Multivariate analysis for five characters in the ten best progenies after two selection cycles revealed significant genetic diversity between the progenies. Selection was successful with the isolation of three productive progenies resistant: to both diseases. The results indicated that seed colour had no influence on resistance m this material and that simultaneous improvement of seed yield, plant type and disease resistance could be achieved.     

Mechanisms and diversity of resistance to sorghum midge, Stenodiplosis sorghicola in Sorghum bicolor

Sorghum midge, Stenodiplosis sorghicola (Coquillett) is the most important pest of grain sorghum worldwide, and plant resistance is an important component for the control of this pest. To identify sorghum genotypes with diverse mechanisms of resistance to sorghum midge, we studied oviposition, larval survival, and midge damage in 27 sorghum midge-resistant genotypes, and a susceptible check under greenhouse conditions. Observations were also recorded on floral characteristics and compensation in grain mass. Of the 28 sorghum genotypes tested, 19 showed high levels of antixenosis to oviposition as a component of resistance, and had <20% spikelets with eggs when infested with 10 or 25 sorghum midge females per panicle under no-choice conditions in the headcage. Genotypes IS 8887, IS 10712, IS 21873, IS 21881, ICSV745, and QL 39 showed antibiosis as one of the components of resistance. Lines IS 7005, IS 10712, IS 18563, IS 21873, IS 21881, PM 15936-2,ICSV 197, and ICSV 745 showed <20% spikelets with eggs, larvae,or, midge damaged chaffy spikelets across infestation levels, compared with >80% midge damaged spikelets in QL 12 - the susceptible check. Genotypes showing resistance to sorghum midge have smaller glumes than the susceptible check, QL 12. However, IS 7005, IS 18653, and ICSV745 have relatively large sized glumes, but suffered <20% midge damage suggesting that factors other than glume size also contribute to midge resistance in sorghum. Fourteen genotypes showed >20% compensation in grain mass when the panicles were reduced to 250 spikelets and infested with 10 or 25 midges per panicle. There is considerable diversity in sorghum genotypes showing resistance to sorghum midge. Genotypes with diverse combination of characteristics associated with resistance to sorghum midge can be used in breeding programs to broaden the genetic base and increase the levels of resistance to this insect. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sorghum [Sorghum bicolor (L.) Moench] landrace variation and classification in North Shewa and South Welo, Ethiopia

Fourteen phenotypic characters were chosen for the purpose of obtaining taxonomic evidence on the resemblances of 177 accessions of sorghum from North Shewa and South Welo regions of Ethiopia. Canonical Discriminant Analysis (CDA) and Modeclus cluster analysis were conducted to see if the 177 accessions could form clusters based on their morphological characters, and to test the consistency of farmers’ naming of the five most common Sorghum landraces represented by 44 accessions. Multivariate analyses grouped the 177 accessions into three clusters linked by a few phenotypic intermediate landraces. A botanical key was established for easy classification of the Sorghum crop plants grown in the study area. The number of accessions of the five most common landraces named by the farmers formed dissimilar groups, suggesting that farmers’ naming of these Sorghum landraces are consistent. Midrib color, grain color, grain size, glume color, glume hairiness, and grain shape were the leading morphological characters used by the farmers in naming these Sorghum landraces. This revised version was published online in July 2006 with corrections to the Cover Date.     

Pattern of genetic inheritance of morphological and agronomic traits of sorghum associated with resistance to sorghum shoot fly, <Emphasis Type="Italic">Atherigona soccata</Emphasis>

Sorghum shoot fly, Atherigona soccata is an important pest of sorghum during the seedling stage, which influences both fodder and grain yield. To understand the nature of inheritance of shoot fly resistance in sorghum, we performed generation mean analysis using two crosses IS 18551 × Swarna and M 35-1 × ICSV 700 during the 2013–2014 cropping seasons. The F₁, F₂, BC₁ and BC₂ progenies, along with the parental lines were evaluated for agronomic and morphological traits associated with resistance/susceptibility to sorghum shoot fly, A. soccata. The cross IS 18551 × Swarna exhibited significant differences between the parents for shoot fly deadhearts (%) in the postrainy season. The progenies of this cross exhibited lower shoot fly damage, suggesting that at least one of the parents should have genes for resistance to develop shoot fly-resistant hybrids. Leaf glossiness, leafsheath pigmentation and plant vigor score during the seedling stage exhibited non-allelic gene interactions with dominant gene action, whereas 100 seed weight showed both additive and dominant gene interactions. Presence of awns showed recessive nature of the awned gene. Generation mean analysis suggested that both additive and dominance gene effects were important for most of the traits evaluated in this study, but dominance had a more pronounced effect.     

Stability of biochemical constituents and their relationships with resistance to shoot fly, Atherigona soccata (Rondani) in seedling sorghum

The stability of biochemical constituents and their association with resistance to shoot fly (Atherigona soccata Rondani) was evaluated for reducing sugars, total sugars, nitrogen, phosphorus, potassium, chlorophyll and moisture contents at weekly intervals of seedling growth (7, 14, 21 and 28 days after emergence) in 14 selected grain sorghum genotypes [five resistant accessions (IS nos. 1054, 2146, 2312, 3962 and 4664); three susceptible checks (CK 60B, CSV 1 and CSH 1); one national variety (CSV 8R); and five post-rainy advanced generation (F₆) breeding lines (148 × CS 3541, SPV 103 × IS 4664, CSV 8R × SPV 104, SPV 104 × M 35-1, and PD 3-1-11 derivative)]. The genotypes IS 2312 and IS 4664 showed stability of antixenosis for oviposition during post-rainy season advanced generation lines compared to the susceptible checks. Deadheart formation was low and the expression of resistance was stable across different seedling growth stages in IS 1054 and IS 2146. Depletion in levels of reducing sugars and phosphorus in resistant genotypes played a significant role in deadheart formation in the test genotypes. Positive association of nitrogen and potassium with oviposition at early seedling stages indicated their role in releasing chemical cues for oviposition. Low levels of reducing sugars and total sugars seemed to enhance the degree of resistance to sorghum shoot fly. The total chlorophyll content had no relationship with antixenosis for oviposition. No relationship was observed between moisture content of sorghum seedlings and shoot fly resistance. Low concentrations of reducing sugars, total sugars, nitrogen, phosphorus and potassium in sorghum seedlings greatly enhanced the degree of antixenosis for oviposition/feeding and deadheart formation, and can be used as selection criteria for resistance to shoot fly.     

Analysis of resistance mechanism to Atherigona soccata in crosses of sorghum

In sorghum, shoot fly resistance is important for grain yield and fodder value. An experiment was conducted to estimate genetic parameters of sorghum for resistance to shoot fly in 50 hybrids, by crossing 5 × 10 genotypes in line × tester manner. Plant height, number of leaves per plant, number of eggs per plant, trichomes on upper and lower surface per unit area of lamina and dead heart per cent were measured on 14 and 21 days after emergence (DAE) and glossiness of leaves was graded on 14 DAE. The correlation between midparent and hybrid performance, GCA : SCA ratio revealed predominance of non-additive gene effects for the traits studied, which could be exploited through hybrid breeding. Of the parents, SPSFPR 94004A and IS 4777 were the best general combiners for shoot fly resistance. Correlation and path analysis revealed the importance of resistance traits and phenol estimation confirms the resistances against shoot fly.     

Identification of sorghum genotypes with resistance to the sugarcane aphid Melanaphis sacchari under natural and artificial infestation

Sugarcane aphid, Melanaphis sacchari is an endemic pest of sorghum during postrainy season, and there is a need to develop cultivars with resistance to this pest. Evaluation of a diverse array of sorghum genotypes under natural and artificial infestation resulted in identification of seven lines (ICSB 215, ICSB 323, ICSB 724, ICSR 165, ICSV 12001, ICSV 12004 and IS 40615) with moderate levels of resistance to aphid damage. Under artificial infestation, 10 lines suffered <20% loss in grain yield as compared to 72.4% grain loss in the susceptible check, Swarna. The genotypes ICSR 165, ICSB 724, IS 40615, DSV 5 and ICSB 323 exhibited moderate levels of resistance to aphid damage (damage rating, DR <5.0) and also had high grain yield potential (>30 q/ha). In another experiment, ICSB 215, ICSB 695, ICSR 161, Line 61510, ICSV 12004, Parbhani Moti and IS 40618 exhibited high grain yield potential (>25 q/ha) and exhibited <50% variation in grain yield as compared to more than 80% in the susceptible check, in CK 60 B. The genotypes RSV 1211, RS 29, RSV 1338, EC 8‐2, PU 10‐1, IS 40617 and ICSB 695 though showed a susceptible reaction to aphid damage, but suffered relatively low loss in grain yield, suggesting that these lines have tolerance to aphid damage. Principal coordinate analysis suggested that the genotypes with aphid resistance are quite diverse and can be used to breed for aphid resistance and high grain yield potential and also in breeding for aphid resistance in sorghum with adaptation to the postrainy season.     

Line selection for exploiting durum wheat (T. turgidum L. var. durum) local landraces in modern variety development program

Summary Pure line selection for grain yield applied within four durum wheat local landraces (Triticum turgidum L. var durum) was studied in an effort to determine: (i) the agronomic performance of selected line mixtures (bulks) and their value as potential new cultivars, (ii) the effectiveness of pure line selection for grain yield within local landraces and (iii) the correlated selection response of yield components and kernel quality traits. Four local durum wheat landraces were used. Two of them, Mytilini-1 and Mytilini-2 are still cropped in some rural areas of the island Mytilini whereas the other two, Limnos and Mavragani are maintained in the Greek Gene Bank. Following their preliminary evaluation for agronomic performance under current growing conditions, 100 individual plants from each landrace were randomly selected. Selected plants (pure lines) were field evaluated head to row during 1997–98 and 1998–99 growing seasons. Based on grain yield performance, bidirectional selection, high vs low, was practised within each landrace. Thus the five higher yielding lines and their corresponding lower ones from each landrace were identified. Selected lines, with no further progeny testing, were pooled using a balanced seed composite to form the high yielding five line bulk and its respective low counterpart. The resulting 16 bulks (eight high and eight low) along with their four source landraces and two commercial varieties, Mexicalli and Simmeto, used as checks, entered field testing for agronomic performance in two and one location during 1999–00 and 2000–01 growing seasons respectively. Data for grain yield and yield components (1000 kernel weight, number of kernels, and productive tillers) along with kernel quality data (protein content and vitreous) were recorded. Data for grain yield indicated that the landraces studied seemed to be line mixtures, as expected, since they responded to bidirectional phenotypic pure line selection. The high yielding bulks were of interesting agronomic performance, equivalent to or significantly better than that of the commercial checks and are worth further testing as potential cultivars. Selected high bulks of Mytilini 2 landrace significantly outyielded both the source landrace and the commercial checks maintaining the high protein content of the source landrace, which was significantly higher than checks. This performance provides evidence that the within landraces selection of lines combining high grain yield with high protein content seems to be feasible. In conclusion, evidence is presented that genetic variability seems to be available within the landraces studied which could be worth using in breeding programs. Furthermore the simple pure line selection breeding effort undertaken seemed to be effective in developing line bulks with promising performance and worth further testing as potential cultivars.     

不同来源高粱品系农艺性状及品质性状遗传多样性分析

选用来自中国、美国、印度的61份高粱品系作为试验材料,采用随机区组设计,成熟期对高粱的9个性状进行统计分析和聚类分析。研究表明,不同品系间性状表现具有丰富多样性,其中生育期和淀粉的变异程度最低,株高、穗长、单宁的变异程度较大,穗粒重、千粒重、粗蛋白、脂肪的变异程度较为明显。株高、穗粒重与穗长呈显著正相关,千粒重与穗粒重呈极显著正相关,单宁、粗蛋白与脂肪呈极显著正相关,单宁、粗蛋白、脂肪与总淀粉呈极显著负相关。聚类分析结果显示,61份高粱品系可划分为三个类群,各类群都表现出独特的地域性特征。供试高粱品系的农艺性状和品质性状均有着巨大的改良潜力,为进一步改良高粱品种和亲本选育提供科学依据。     

热带糯质高粱种质选育及改良利用

旨在分析热带糯质资源在高粱育种中的利用价值及对杂种优势的影响,以商丘市农林科学院自有种质作为研究对象,导入热带糯质资源,选育出稳定的不育系,并对所配组合的农艺性状进行方差及相关性分析。结果表明：‘M17A’所配组合的产量、穗粒重、单穗重等性状与其他组合比较均达到极显著水平,组合8的小区产量最高,为15.17 kg;穗部各性状与产量间的相关系数依次为穗粒重>单穗重>穗长>千粒重>轴长>着壳率>角质率,穗粒重与产量的相关系数为0.957,呈极显著正相关,说明在高粱高产育种中,应重点选择穗大、结实率高的种质;‘M17A’所配组合的淀粉含量与其他组合比较均达极显著水平,说明高粱淀粉含量受遗传基因控制。对于热带种质的利用应选择大穗型,角质率低的材料。     

Genotypic resistance in sorghum to head bug,Calocoris angustatus Lethiery

Summary Sorghum head bug, Calocoris angustatus Leth., is an important pest of grain sorghum. We screened nearly 15000 germplasm accessions for resistance to this pest between 1980 and 1990 under natural and headcage conditions. Data were recorded on bug numbers, grain damage (1 = highly resistant the 5 = highly susceptible), and seed germination. Under natural conditions, 34 genotypes suffered moderate levels of grain damage (damage rating (DR) 1.7 to 2.9) compared with a DR of 4.0 to 4.6 in the susceptible controls CSH 1, CSH 5 and CSH 9. IS 17610, IS 17645, IS 21444, IS 19948, IS 25069 and IS 19949 suffered a DR of less than three, and harbored less than 150 bugs/panicle compared with a DR of 4.3 to 4.7, and 248 to 353 bugs/panicle in the susceptible controls CSH 1, CSH 5 and CSH 9 when infested under headcage with 5 pairs of bugs/panicle. IS 18274, IS 20664, IS 20059, IS 25069, and IS 19951 had 150 to 300 bugs/panicle but suffered moderate levels of grain damage (DR less than 3), while the reverse was true in case of IS 8064, IS 19455, IS 19955, IS 20024, IS 20740, IS 23627, IS 2761, and IS 9692. During the 1989 rainy season, IS 14108, IS 17610, IS 17618, IS 17645, IS 19949, IS 19950, IS 19957, IS 20068, IS 25760, IS 27452, IS 27477 and IS 27329 suffered moderate levels of grain damage when infested with 5 and 10 pairs of bugs/panicle, and recorded more than 80% seed germination compared with a DR of 3.9 to 5.0, and seed germination of 15–18% in the susceptible controls CSH 1, CSH 5 and CSH 9. There is a considerable diversity in the genotypes resistant to head bugs, and attempts should be made to transfer the resistance into agronomically acceptable cultivars.     

A major QTL for plant height is linked with bloom locus in sorghum [Sorghum bicolor (L.) Moench]

Plant height is one of the most important agronomic traits in sorghum with its relevance for biomass, grain yield, fodder and lodging. To understand its genetic basis, the quantitative trait loci (QTL) were identified using a recombinant inbred line (RIL) population consisting of 168 RILs derived from the cross between the two sorghum inbred lines 296B (dwarf) and IS18551 (tall) over six seasons. Two major QTL were identified one each on chromosomes SBI-06 and SBI-07 corresponding to the Dw2 and Dw3 gene loci together accounting 41 % plant height variation. In addition, a morphological bloom trait locus which remained unlinked in the linkage map was found to be significantly linked with plant height in single marker analysis explaining 22 % of the trait variation. By comparing the map positions of Dw1, Dw2 and Dw3, the new locus for plant height linked with bloom is proposed as Dw4 locus. Both SSR and the morphological bloom loci linked with height QTL of the present study can be employed as effective tools in marker-assisted breeding for rapid conversion of selected inbred parent lines either as dwarf seed (male sterile) parents or taller pollinators for hybrid seed industry, or for developing high biomass lines in sweet sorghum for exploitation as high bio-fuel crop.     

Spanish barley landraces outperform modern cultivars at low‐productivity sites

Barley landraces from the western Mediterranean area have not been thoroughly exploited by modern breeding. This study aims at assessing the agronomic value of a core collection of lines derived from landraces of Spanish origin and to compare them with sets of successful old and modern cultivars. The agronomic performance of a set of 175 barley genotypes, comprising 159 landrace‐derived lines and 26 cultivars, was evaluated in a series of 10 field trials, carried out over 3 years and several locations. The most relevant trait of the landraces was higher grain yield at low production sites than cultivars, which may be related with better ability to fill the grain under stressful conditions. On the other hand, lateness, excessive plant height and lodging were negative traits frequently found in the landraces. Large genotype‐by‐environment interaction (GEI) for grain yield was detected, related partly with differences between germplasm groups, probably indicating local adaptation. GEI was also associated with the interaction of heading time and powdery mildew resistance with temperature.     

Near-isogenic lines of durum wheat: their development and plant characteristics

Summary The effect of specific plant characteristics on the grain and biomass yield of durum wheat can be accurately determined by using isogenic lines, which, however, were not usually available. This study reported the effects of long glume, glaucousness, glume pubescence, black glume and purple culm on the yield and its associated characteristics in near-isogenic lines of durum wheat cv. LD222, which were developed by continuous backcrossing. The long glume trait which resulted in a large photosynthetic area did not enhance yield. Increased glume size associated with the P gene tended to increase the main culm dominance, characterized such as vigorous main culm and weak tillers, and plant height, but to reduce tillering and spike number. Consequently, grain yield and harvest index declined. Under the adequate water supplying condition of the present study, the glaucous trait was beneficial for grain yield. The trait of glume pubescence did not excert any significant effect on the yield related characteristics in the LD222 background. The traits of black glume and purple culm reduced the number of spikes per unit area and the number of kernels per unit area.     

Variation between and within Ethiopian barley landraces

Up to 100 single plant derived lines of 18 barley landraces, collected from 18 localities of six barley growing regions of Ethiopia were studied for two years at Holetta, Ethiopia for variation in five quantitative traits; scald severity, earliness, plant height, 1000 grain weight, and leafiness. The relative latent period in the adult plant stage to barley leaf rust, a good measure for partial resistance, was assessed on the landrace lines at Wageningen, The Netherlands. The observed variation between and within landraces was very large for all traits. The magnitude of variation was so large that most, if not all, plants within a landrace had a different genotype. The landraces also varied in the degree of variation. Some landraces, 1726 and 3288 for instance, were more variable for most or all traits than other landraces such as 208925 and 212938. Days to heading and scald severity were significantly (P = 0.01) correlated with altitude, r being 0.66 and - 0.65, respectively. Resistance to scald and leafiness also increased with altitude. On average landraces became later, more resistant to scald and more leafy the higher the altitude of collection. This associated complex of traits could be an adaptation to the wetter and cooler conditions at higher altitudes. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

In vitro protein digestibility in grain sorghum: effect of genotype and interaction with starch digestibility

Improvement of nutritive value is one of the main goals of sorghum breeding. It is known that one of the reasons of relatively poor nutritive value of sorghum grain is resistance of its seed storage proteins (kafirins) to protease digestion that also affects digestibility of starch. To study genetic aspects and interdependency of these traits we investigated in vitro protein and starch digestibility of the flour of 12 grain sorghum lines and six F₁ hybrids. Comparison of SDS-PAGE spectra of total grain proteins before and after pepsin digestion revealed that the F₁ hybrids had significantly lower indices of protein digestibility than parental lines, with the exception of the F₁ hybrid M35-1A KB/KVV-45, which retained high level of protein digestibility typical for KVV-45 line. The level of starch digestibility in the F₁ hybrids corresponded to its level in maternal lines suggesting importance of maternal genotype in determination of this trait. It was found that starch digestion by amylolytic enzymes increased the amount of protein in individual kafirin fractions, and reduced the amount of high molecular weight proteins as well it reduced subsequent kafirin digestion by pepsin and caused formation of polypeptide (M_r ~45 kDa), perhaps, the kafirin dimer, resistant to pepsin digestion. These data are of importance for fundamental investigation of factors influencing kafirins and starch interactions in sorghum endosperm and their digestibility.     

Pattern of variation for seed size traits and molecular markers in Italian germplasm of Phaseolus coccineus L.

Variation in Italian germplasm of Phaseolus coccineus L. was assessed for seed traits and molecular markers. A total of 130 seeds and seedlings, five for each of 21 Italian landraces, an Italian commercial cultivar and four Mesoamerican landraces of P. coccineus, were analysed using seven selected PCR markers: three RAPDs, two ISSRs and two ETs. Seed weight of the Mesoamerican landraces was ≤1 g, whereas that of the Italian landraces varied from 1 g to 2.5 g and was related to their origin. Oval shape was more frequent, with round shape observed only in Mesoamerican landraces. Three seed coat colours were observed: white, violet mottled or spotted black and buff spotted brown, also this trait was related to the origin. The level of polymorphism detected by molecular markers was low but with significant discriminant power. ISSRs were the most effective markers prone to unravel molecular polymorphism. The within accession component of variation exceeded that among accessions, as expected for an allogamous species. However correct classification of the individuals was achieved performing either discriminant analysis of the seed phenotypic traits or cluster analysis of seedling similarity measure based on the whole banding patterns obtained by the three marker types. Our data suggest that the Italian farmers, starting with ancestral Mesoamerican runner bean introductions in Europe, bred their own landraces through selection for seed size and seed coat colour, but occasional gene flow maintained variability within landraces bred by different farmers in the same Italian Region. Selection favored molecular and seed trait uniformity within several landraces making them suitable for certification.