Heritabilities of nutritive quality factors and interrelationships with yield in selected progenies of tall fescue

Nine polycross (PX) and nine different self (S₁) progenies were randomly chosen from 43 selected tall fescue genotypes and evaluated for in vitro digestible organic matter (IVDOM), crude protein, neutral detergent fibre, acid detergent fibre and acid detergent lignin of whole plants, leaf blades and stems (stem plus leaf sheath) at each of four harvest dates in 1991 and 1992. Significant variation for all whole‐plant and leaf quality traits occurred among the PX progenies at the May harvest. Variation among S₁ progenies was significant for almost all of the stem traits. Genetic variance components for both progeny groups were significant for almost all of the traits, confirming the presence of additive genetic variation. Heritability estimates on a progeny‐mean basis ranged from medium to high for almost all the traits of the whole‐plant and the leaf and stem fractions. The results suggest that spring would be the time at which direct selection for high IVDOM or low fibre content would be successful and that selection for leaf or stem quality traits improves whole‐plant quality. Selection for quality traits in the summer or in the autumn would be difficult since no significant genetic variability was found.     

Genetic basis of nutritional content of stover in maize under low nitrogen conditions

The effect of two different nitrogen treatments on five traits associated with yield and nutrient composition of stover were evaluated using a set of 213 F_2:3 families derived from two elite inbred lines Huang-C and Xu178. Evaluation of the phenotypes expressed under the two nitrogen conditions showed that low nitrogen conditions could increase acid detergent fiber (ADF) and neutral detergent fiber (NDF), and decreased crude protein content (CP), crude fat content (CF), and stover yield (SY), thereby negatively affecting the digestibility and quality of silage maize. Twenty-eight quantitative trait loci (QTL) were identified affecting the five measured traits under two nitrogen conditions, including four for ADF, five for NDF, five for CP, four for CF, and three for SY. Several QTL associated with ADF or NDF were detected under same nitrogen conditions, and were localized to the same chromosomal regions, especially the QTL qADF6 and qNDF6, qADF10 and qNDF10, were only detected under low nitrogen condition. These results suggested that ADF and NDF perhaps were controlled by several common genes, and that the nutritional content of stover may be influenced by additional genetic mechanisms when grown under conditions of low nitrogen.     

我国常用玉米自交系秸秆品质性状及其相关分析

利用近红外反射光谱法对我国91份常用普通玉米自交系和11份高油自交系秸秆的体外干物质消化率（IVDMD）、粗蛋白（CP）、粗脂肪（EE）、可溶性糖（WSC）、酸性洗涤纤维（ADF）、酸性木质素（ADL）、中性洗涤纤维（NDF）7个品质性状进行了分析评价,以探讨秸秆品质性状间的关系以及影响秸秆品质的主要成分。结果表明,各品质性状变异较大,各性状自交系间差异均达极显著水平,IVDMD及其相关品质的含量近似正态分布。不同品质性状变异程度不同,其中WSC含量变异最大,变异系数达33.15%。IVDMD与NDF、ADF、ADL呈极显著负相关,与WSC、EE含量呈极显著正相关,与CP含量显著正相关。影响秸秆品质的性状依次是IVDMD、ADF、NDF、WSC、ADL、CP和EE含量。根据青贮玉米育种的要求,筛选出5份IVDMD和WSC含量高、NDF、ADF含量低的自交系。     

Yield and Forage Quality of Different ×Festulolium Cultivars in Winter

×Festulolium ssp. are of particular interest as autumn‐saved herbage in the winter grazing system, but information concerning their performance in this low‐input system is not available. To this end, we examined dry matter (DM) yield and forage quality in winter of four different cultivars of ×Festulolium ssp. (×Festulolium pabulare, Festulolium braunii), either with festucoid or loloid attributes, compared with Festuca arundinacea Schreb. Furthermore, pre‐utilization (accumulation since June or July) and date of winter harvest (December or January) were varied examining the influence of different sward management. DM yield, crude protein, metabolizable energy (ME) (in vitro rumen fermentation technique), acid detergent fibre (ADF) and ergosterol concentration were determined. Within all years, the festucoid cultivars (mean 3.4 t ha^?1) attained significant higher yields during winter than the loloid cultivars (mean 1.6 t ha^?1), but their yields were comparable with F. arundinacea (mean 3.0 t ha^?1). Crude protein was decisively influenced by the different yield levels of the cultivars resulting in higher values for the loloid cultivars. Energy concentrations decreased with later winter harvest, whereas ADF as well as ergosterol concentrations frequently increased from December to January. The greatest differences between festucoid and loloid cultivars were generally observed during severe winters. Obviously, the festucoid cultivars were better adapted to a utilization as autumn‐saved herbage than the cultivars with rather loloid attributes. However, the hybrids did not surpass F. arundinacea regarding yield and quality.     

Quantitative trait loci mapping of forage stover quality traits in six mapping populations derived from European elite maize germplasm

Four forage maize stover quality traits were analysed including in vitro digestibility of organic matter (IVDOM), neutral detergent fibre (NDF), water‐soluble carbohydrates (WSC) and digestibility of NDF (DNDF). We mapped quantitative trait loci (QTL) in three DH (doubled haploid) populations (totally 250–720 DH lines): one RIL population (358 lines) and two testcross (TC) populations, based on field phenotyping at multiple locations and years for each. High phenotypic and genotypic correlations were found for all traits and significant (p < .01) at two locations, and NDF was negatively correlated with the other traits. QTL analyses were conducted by composite interval mapping. A total of 33, 23, 32 and 25 QTL were identified for IVDOM, NDF, WSC and DNDF, respectively, with three, four, five and two major QTL for each. Few consistent QTL for IVDOM, WSC and DNDF were detected in more than two populations. This study contributed to the identification of key QTL associated with forage maize digestibility traits and is beneficial for marker‐assisted breeding and fine mapping of candidate genes associated with forage maize quality.     

Chemical Composition and In Vitro Digestibility of Whole-Crop Pea and Pea–Cereal Mixture Silages Grown in South-western Quebec

The objective of this study was to determine the chemical composition and in vitro dry matter (IVDMD) and neutral detergent fibre (IVNDFD) digestibilities of silages made from whole‐crop pea [Pisum sativum L. (PS)], pea–wheat [Triticum aestivum L. (PW)], pea–barley [Hordeum vulgare L. (PB)] and pea–oat [Avena sativa L. (PO)] mixtures harvested 8 weeks (H8) and 10 weeks (H10) after seeding. Forty‐five days after ensiling, all forages were well ensiled as indicated by low pH and low water‐soluble carbohydrate content and high lactic acid concentration. Regardless of forage type, crude protein (CP) and IVNDFD were higher while starch and acid detergent lignin were lower in H8 than H10. However, harvest date had no effect on neutral (NDF) and acid (ADF) detergent fibre of the silages. Within each harvest date, CP was higher while NDF was lower for PS than pea–cereal silages. Differences in CP and fibre fractions between the pea–cereal mixture silages were not consistent for the two harvest dates. The IVDMD of PS was higher than that of the three pea–cereal mixture silages in H8 but was only higher than that of PB in H10. For the pea–cereal mixtures, IVDMD was higher for PO than PB and PW in H8 and was higher for PB than PW in H10. It was concluded that silage from pea monoculture had similar forage yields and a generally higher nutritive value than silages from pea–cereal mixtures.     

Genetic variation and heritability of forage yield in Mediterranean tall fescue

The genetic control of tall fescue forage yield has been poorly investigated. Full‐sib families from diallel crosses of Mediterranean germplasm were evaluated for forage yield over 34 months in a Mediterranean environment with severe drought stress (diallel 1, with 20 parents) and over 16 months under irrigation in a heated greenhouse simulating the Mediterranean temperature pattern (diallel 2, with 15 parents). Genetic parameters were estimated for fresh biomass in diallel 1 and dry‐matter yield in diallel 2. Additive genetic variance was always larger than non‐additive (dominance) variance. Narrow‐sense heritability was fairly high (h² = 0.61) in diallel 1 and moderate (h² = 0.45) in diallel 2. Predicted yield gains from one selection cycle were larger in the former diallel (23.9%) than in the latter (10.5%), suggesting that gains can be enhanced by selection under severe drought stress and over a time span sufficient to allow the variation in persistence to fully emerge. General combining ability effects of eight parents that were common to both diallel crosses were highly correlated (r = 0.94) across the contrasting evaluation environments. The extent and consistency of additive genetic effects across environments suggest that rapid improvement of forage yield is possible.     

Influence of Sowing and Harvest Time on Fibre Flax (Linum usitatissimum L.) in the Mediterranean Environment

Triennial field trials were carried out at Viterbo, central Italy, to investigate the influence of the sowing time, nitrogen fertilization and harvest dates of the two fibre flax (Linum usitatissimum L.) varieties Belinka and Ariane. Our results showed that warm and dry weather conditions, prevailing from late spring onwards, caused excessive shortening of the growing cycle of spring crops, with negative consequences for seed and fibre yield and quality. However, autumn sowings gave interesting results. Stem dry weight ranged between 5.6 and 6.7 t ha^?1 for autumn sowings and between 1.9 and 4.1 t ha^?1 for spring sowings. In autumn sowings, plant height and seed yields were also increased. Seed germinability was good even for early harvest dates. Stem dry weight remained constant at harvest dates following yellow‐green ripening, indicating that biomass was no longer allocated to the stems after that phase.     

Condensed tannins in birdsfoot trefoil: Genetic relationships with forage yield and quality in NC-83 germplasm

Summary Genetic relationships of condensed tannins (CT) with other forage quality parameters have not been adequately studied in birdsfoot trefoil (Lotus corniculatus L.). The objectives were to bidirectionally select for CT concentration in birdsfoot trefoil to determine selection response and to create populations for examination of genetic relationships of CT with forage quality parameters, principally lignin. High-and low-tannin parental clones were selected from NC-83 birdsfoot trefoil germplasm and intercrossed to produce Syn₁ populations. Herbage samples, harvested for two years at two locations, were analyzed from high-tannin, low-tannin, and parental populations for CT concentration, herbage yield, and forage quality parameters. The mean condensed tannin concentrations in the high-and low-tannin populations were 69.3±0.8 and 21.1±0.8 g catechin equivalent (CE) kg^-1 dry matter (DM) compared with 36.4±0.8 g CE kg^-1 DM in the parental population. The selection response exhibited a quadratic relationship, with selection for increased CT concentration more effective than for reduced CT concentration. Compared with the parental population, acid detergent lignin (ADL) was higher, and crude protein (CP) and in vitro digestible dry matter (IVDDM) concentrations were lower for the high-tannin population and the converse was true for the low-tannin population. Lignin concentration was positively correlated with CT concentration (r_g=0.66 P0.01).Abbreviations ADF acid detergent fiber - ADL acid detergent lignin - CP crude protein - CT condensed tannins - IVDDM in vitro digestible dry matter - NDF neutral detergent fiber - NIRS near infrared reflectance spectroscopy     

Evaluation of environments for preliminary testing of maize for yield and stover digestibility

Summary The identification of environments suitable for selection should enable plant breeders to test reliably a larger number of genotypes with given resources. This research was undertaken to evaluate discrimination ability (DA) and prediction ability (PA) of eight environments involving two locations. Eckartsweier (Eck) 1 and Voelkenrode (Voe); 2 yer. 1984 (84) and 1985 (85); and two harvests, silage harvest (I) and later (II). It was based on dry matter yield of plant (PDMY), ear (EDMY) and stover (SDMY) and on in vitro digestible organic matter (IVDOM), neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) of stover of 12 inbred lines and their 66 diallel crosses in maize (Zea mays L.). Linear regression coefficient of the performance of genotypes in an environment on that averaged across all environments and its degree of determination were used as measures of the DA and PA of environments, respectively. In hybrids, the DA of environments differed significantly for all traits except SDMY and ADL. Environment Eck851 showed better PA (0.63) than other environments for PDMY, EDMY, IVDOM, NDF, and ADF. Among the 12 two-environment combinations. EckI was a better predictor for PDMY, EDMY, IVDOM and NDF (PA0.80). The more productive environments showed better DA and PA for PDMY and FDMY than less productive ones. For IVDOM and NDF the first harvest provided better discrimination and prediction than the second harvest. In inbred lines the DA of environments differed significantly for EDMY only. In the present study, PA and DA seemed to be functions of the environments, PA was improved by combining two environments, and some environments seemed to be suitable for preliminary selection of genotypes for such diverse traits as yield and digestibility.     

Evaluation of Near Infra-red Reflectance Spectroscopy for Predicting Grain and Stover Quality Traits in Maize

The prediction of grain and stover quality parameters in maize {Zea mays L.) by near infra-red reflectance spectroscopy (NIRS) was studied. A total of 110 grain and 135 stover samples originating from different genotypes and environments were assayed. Calibration equations for content of crude protein (CP), crude fat (CF), starch (ST), and water soluble carbohydrates (WSC) in grain were obtained by multiple linear regression of known manual values on NIRS data from the odd numbered samples. Calibrations for CP, acid detergent fibre (ADF), in vitro digestible organic matter according to the Tilley & Terry (IVDOM-T & T) and the gas production (IVDOM-Gp) method, respectively, and metabolizable energy (ME) in stover were developed analogously. Equations were validated with the evennumbered .samples and for ME additionally with the 1584 stover samples from an experiment with 66 F₁ hybrids tested in six environments. The coefficients of multiple determination (R²) of the prediction equations ranged from 0.80 for IVDOM-Gp and ME in stover to 0.94 for CP in grain. Standard errors of calibration (SEC) and prediction (SEP) were in most cases not higher than commonly reported for conventional manual assays. With regard to the correct ranking of hybrids, prediction equations for ME applied well to stover samples from other environments with one exception. We concluded that NIRS can evaluate the quality traits investigated to a similar degree to that of conventional methods of analysis. Since NIRS is simple and safe to operate and allows rapid screening of several quality traits simultaneously, it should be particularly attractive for breeding purposes.     

Assessing for genetic and environmental effects on ruminant feed quality in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis>)

Grain samples from a combined intermediate and advanced stage barley breeding trial series, grown at two sites in two consecutive years were assessed for detailed grain quality and ruminant feed quality. The results indicated that there were significant genetic and environmental effects for “feed” traits as measured using grain hardness, acid detergent fibre (ADF), starch and in-sacco dry matter digestibility (ISDMD) assays. In addition, there was strong genotypic discrimination for the regressed feed performance traits, namely Net Energy (NE) and Average Daily Gain (ADG). There was considerable variation in genetic correlations for all traits based on variance from the cultivars used, sites or laboratory processing effects. There was a high level of heritability ranging from 89% to 88% for retention, 60% to 80% for protein and 56% to 68% for ADF. However, there were only low to moderate levels of heritability for the feed traits, with starch 30–39%, ISDMD 55–63%, ADF 56–68%, particle size 47–73%, 31–48% NE and ADG 44–51%. These results suggest that there were real differences in the feed performance of barleys and that selection for cattle feed quality is potentially a viable option for breeding programs.     

Effect of Genotypes and Plant Maturity on Forage Quality of Certain Forage Legume Species Under Rainfed Conditions

Evaluation of plant species for animal feed requires the quantitative and qualitative comparison of different genotypes. Promising lines of annual legumes comprising seven genotypes of vetche ( Vicia spp.) and chicklings ( Lathyrus spp.) were compared for herbage quality. The content of crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in herbage and pods were measured at different stages of plant maturity. The proportion of the leaves to shoots (leafiness) and in vitro dry matter digestibility (IVDMD) were also determined. As plants matured IVDMD, CP and leafiness decreased and NDF and ADF increased. For all the genotypes maximum digestible dry matter (DDM) and CP yields were more or less attained at 50–100 % podding. Narbon vetch had the highest DDM. The possible uses of the different genotypes as animal feed are discussed based on the partitioning of the DDM and CP yield as plants matured.     

Influence of Slight Shading, Sward Density and Nitrogen Fertilization on Yield and Nutritive Value of Lolium multiflorumo Lam.

In a two year factorial field trial the influence of slight shading (daylight reduced by 27 %), row spacing (15 and 30 cm respectively) and N fertilization (60 and 120 kg* ha^?1*cut^?1 respectively) on yield and nutritive value of Lolium multiflorum (Lam.) was investigated. Three cuts were taken in the seeding year and four in the full harvest year. Shading reduced DM yield by 4 % at low and 16 % at high level of N fertilization. Higher amount of N fertilizer increased yield by 28 % without and 12 % with shading. Row spacing was of minor importance; on average wider spacing decreased yield by 9 %. Increasing N fertilization and shading had the same effects on nutritive value: crude protein (CP), nitrate content and protein/energy ratio (P/E) went up, whereas energy value (NEL) went down. Compared to the effects of shading or N fertilization, the influence of sward density on nutritive value was small. The effect of shading and high fertilization on nutritive value was similar in both years. However for vegetatively grown forage in the seeding year shading caused P/E values and nitrate contents too high for an adequate ruminant feeding which was already evident at low level of N fertilization; also increased supply of N fertilizer without shading deteriorated the nutritive value. On the other hand forage of the full harvest year (at reproductive stages) showed too high P/E values only in shaded and highly fertilized plots. Therefore N fertilization ought to be limited at periods when the grass only grows vegetatively and/or light intensity is low, like e.g. in autumn. None of the experimental treatments had any marked effect on the fibre content of the forage (ADF) in the seeding year; in the full harvest year, however, when plants grew reproductively, shading as well as higher N fertilization increased ADF content. There was no significant correlation between ADF and NEL for vegetatively grown plants but a close relation for plants which were at reproductive stages.     

Defoliation Regime Effects on Accumulated Season-long Herbage Yield and Quality in Boreal Grassland

Within boreal grasslands, little information exists on the effects of initial defoliation date, frequency, and intensity on accumulated herbage yield and quality. We investigated the effects of initial defoliation in May, June or July, at heights of 5, 10 or 15 cm, and repeated at 2‐, 4‐ or 6‐week intervals throughout the growing season. Harvested material was combined with year‐end residual biomass, and examined for herbage removed, crude protein (CP), crude protein yield (CPY) and neutral detergent fibre (NDF). Compared to single defoliated check plots, total, grass and forb dry matter (DM) yields were lower under repeated defoliation by 25, 38 and 17 %, respectively. The majority of total herbage produced was harvested in the spring clipping. Total, grass and forb DM yields peaked under moderate (10 cm) clipping. Total DM and grass biomass were maximized with long (6 week) recovery periods. In contrast, forb biomass was greatest with May defoliation followed by a 4‐week interval. While maximum grass CPY was found under 10‐cm defoliation, forb CPY peaked with early and moderate to intensive defoliation. These results indicate that season‐long herbage biomass, along with CPY, can be maximized in boreal grasslands through controlled defoliation.     

不同保存方法对秸秆营养价值的影响

研究高粱秸、玉米秸、豆秸和甘薯藤4种秸秆在不同保存方法（露天保存、棚舍保存、青贮和氨化）下主要营养物质的变化情况。并选用2头安装有永久性瘤胃瘘管的去势本地黄牛(450±15kg)来研究不同保存方法对其DM、OM、NDF和ADF瘤胃降解率的影响。结果表明：不同保存方法对CP影响差异极显著(P<0.01)；对OM高粱秸差异极显著(P<0.01)，甘薯藤差异显著(P<0.05)；NDF差异均显著(P<0.05)；ADF差异均显著(P<0.05)，WSC差异极显著(P<0.01)；提高DM、OM、NDF和ADF降解率的方法为烘干，氨化，豆秸除外。     

Genetic association of within‐boll yield components and boll morphological traits with fibre properties in upland cotton (Gossypium hirsutum L.)

Knowledge of genetic relationships between within‐boll yield components and fibre quality is essential for simultaneous improvement of lint yield and fibre quality in upland cotton (Gossypium hirsutum L.). Nine parents and their F₁ progeny with reciprocals from a 3 × 6 factorial mating design were grown in 2008 and 2009. Seven within‐boll yield components and two boll morphological traits and the three fibre quality parameters were analysed based on a conditional additive/dominance (AD) genetic model. Results showed that boll length contributed to the largest proportion of phenotypic, additive and dominance variances for UHM length; seed index contributed to the largest proportion of phenotypic and additive variances for fibre strength; boll width made the largest contribution to phenotypic and additive variances and the second largest contribution to dominance‐by‐environment interaction variance for micronaire, indicating that they played an important role than the other traits for fibre length, strength and fineness/maturity, respectively. It is worthy of note that those correlations between boll shape and fibre quality apply only to the nine parents and the resultant hybrids in this study and do not imply a cause and effect relationship.     

Assessment of Groundnut under Combined Heat and Drought Stress

In semi‐arid regions, particularly in the Sahel, water and high‐temperature stress are serious constraints for groundnut production. Understanding of combined effects of heat and drought on physiological traits, yield and its attributes is of special significance for improving groundnut productivity. Two hundred and sixty‐eight groundnut genotypes were evaluated in four trials under both intermittent drought and fully irrigated conditions, two of the trial being exposed to moderate temperature, while the two other trials were exposed to high temperature. The objectives were to analyse the component of the genetic variance and their interactions with water treatment, year and environment (temperature) for agronomic characteristics, to select genotypes with high pod yield under hot‐ and moderate‐temperature conditions, or both, and to identify traits conferring heat and/or drought tolerance. Strong effects of water treatment (Trt), genotype (G) and genotype‐by‐treatment (GxTrt) interaction were observed for pod yield (Py), haulm yield (Hy) and harvest index (HI). The pod yield decrease caused by drought stress was 72 % at high temperature and 55 % at moderate temperature. Pod yield under well‐watered (WW) conditions did not decrease under high‐temperature conditions. Haulm yield decrease caused by water stress (WS) was 34 % at high temperature and 42 % under moderate temperature. Haulm yield tended to increase under high temperature, especially in one season. A significant year effect and genotype‐by‐environment interaction (GxE) effect were also observed for the three traits under WW and WS treatments. The GGE biplots confirmed these large interactions and indicated that high yielding genotypes under moderate temperature were different to those at high temperature. However, several genotypes with relatively high yield across years and temperature environments could be identified under both WW and WS conditions. Correlation analysis between pod weight and traits measured during plant growth showed that the partition rate, that is, the proportion of dry matter partitioned into pods, was contributing in heat and drought tolerance and could be a reliable selection criterion for groundnut breeding programme. Groundnut sensitivity to high‐temperature stress was in part related to the sensitivity of reproduction.     

Spring Cereals for Forage and Grain Production in a Cool Maritime Climate

Newfoundland's climate is marginal for agricultural production. The availability of locally grown cereal grain and high‐quality forage are major limitations to successful animal agriculture in this region. Here, our overall objective was to compare several spring cereal species for both annual forage and grain production in Newfoundland's cool Maritime climate. Several varieties of barley (Hordeum vulgare L.), wheat (Triticum aesitivum L.), oats (Avena sativa L.) and pea (Pisum sativum L.)–cereal mixtures for forage yield and quality, as well as grain yield and maturity, were compared in field trials on the east and west coasts in both 1999 and 2000. Barley headed earliest, yielded greatest forage dry matter, had lowest forage protein and acid detergent fibre (ADF) percentages, and had neutral detergent fibre (NDF) mean values greater than those of pea–cereal mixtures, but less than those of oats and wheat. Forage harvested from pea–cereal mixtures was similar to that of barley for yield, ADF and NDF, while P and protein percentage were much greater. Barley matured 10–15 days earlier than both wheat and oats. In general terms, all three spring cereals exhibited similar grain yield potential. Oats tillered less, but compensated by producing more kernels spike^?1. Days to maturity for cereal grains in western Newfoundland were roughly similar to those reported for the Maritime provinces of Canada. Yield and maturity results for both forage and grain production suggest that eastern Newfoundland is a unique agro‐ecoregion in North America, and agronomic recommendations specific to other regions may not be applicable in this region.     

Agronomic and genetic diversity in intermediate wheatgrass (Thinopyrum intermedium)

Intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] plant introductions (PI) have played a critical role in the development of improved intermediate wheatgrass cultivars. The objective of this study was to characterize a large number of intermediate wheatgrass populations over its native range for dry matter yield (DMY), crude protein (CP), in vitro true digestibility (IVTD), neutral detergent fibre (NDF), and rhizome development and genetic diversity and structure to identify superior populations and possible geographical regions in which to collect. Analysis of molecular variance using 643 AFLP bands partitioned 31% of the total genetic variation among these populations with 69% variance detected within populations. Bayesian cluster analysis identified two large groups designated as Asian and European under K = 2. In general, European accessions had greater DMY than did Asian accessions. Observed trends were towards greater CP values in populations with Asian ancestry. Selection index values above zero were observed in populations with European ancestry, and the exception was the late‐maturing (208 days to bloom) populations with Asian ancestry. Plant populations 383 551, 383 561, 401 161, 401 173, 440 021, 578 692 (cv. Tegmar) and 598 740 had rhizome scores greater than 7.0. Despite significant differences detected between populations (Φ_ST = 0.3136; P < 0.001), there was strong indication of admixed co‐ancestry or possible gene flow between K = 2–9 models.