The association among herbivory tolerance,ploidy level,and herbivory pressure in <Emphasis Type="Italic">cardamine pratensis</Emphasis>

We tested whether differences in ploidy level and previous exposure to herbivory can affect plant tolerance to herbivory. We conducted a common garden experiment with 12 populations of two ploidy levels of the perennial herb Cardamine pratensis (five populations of tetraploid ssp. pratensis and seven populations of octoploid ssp. paludosa). Earlier studies have shown that attack rates by the main herbivore, the orange tip butterfly Anthocharis cardamines, are lower in populations of octoploids than in populations of tetraploids, and vary among populations. In the common garden experiment, a combination of natural and artificial damage significantly reduced seed and flower production. We measured tolerance based on four plant-performance metrics: survival, growth, seed production and clonal reproduction. For three of these measurements, tolerance of damage did not differ between ploidy levels. For clonal reproduction, the octoploids had a higher tolerance than the tetraploids, although they experience lower herbivore attack rates in natural populations. Populations from sites with high levels of herbivory had higher tolerance, measured by seed production, than populations with low levels of herbivory. We did not detect any significant costs of tolerance. We conclude that high intensity of herbivory has selected for high tolerance measured by seed production in C. pratensis.     

Do ploidy level and nuclear genome size and latitude of origin modify the expression of <Emphasis Type="Italic">Phragmites australis</Emphasis> traits and interactions with herbivores?

We studied the relationship between genome size and ploidy level variation and plant traits for the reed grass Phragmites australis. Using a common garden approach on a global collection of populations in Aarhus, Denmark, we investigated the influence of monoploid genome size and ploidy level on the expression of P. australis growth, nutrition and herbivore-defense traits and whether monoploid genome size and ploidy level play different roles in plant trait expression. We found that both monoploid genome size and latitude of origin contributed to variation in traits that we studied for P. australis, with latitude of origin being generally a better predictor of trait values and that ploidy level and its interaction with monoploid genome size and latitude of origin also contributed to trait variation. We also found that for four traits, tetraploids and octoploids had different relationships with the monoploid genome size. While for tetraploids stem height and leaf water content showed a positive relationship with monoploid genome size, octoploids had a negative relationship with monoploid genome size for stem height and no relationship for leaf water content. As genome size within octoploids increased, the number of aphids colonizing leaves decreased, whereas for tetraploids there was a quadratic, though non-significant, relationship. Generally we found that tetraploids were taller, chemically better defended, had a greater number of stems, higher leaf water content, and supported more aphids than octoploids. Our results suggest trade-offs among plant traits mediated by genome size and ploidy with respect to fitness and defense. We also found that the latitude of plant origin is a significant determinant of trait expression suggesting local adaptation. Global climate change may favor some genome size and ploidy variants that can tolerate stressful environments due to greater phenotypic plasticity and to fitness traits that vary with cytotype which may lead to changes in population genome sizes and/or ploidy structure, particularly at species’ range limits.     

Low-copy nuclear DNA sequences reveal a predominance of allopolyploids in a New Zealand Asplenium fern complex

Recent generalisations about polyploidy in plants have been largely based on studies of angiosperms. A compelling group to compare with angiosperms is ferns, because of their high polyploidy. The bi-parental inheritance of nuclear DNA sequence markers makes them advantageous for investigating polyploid complexes, but few such markers have been available for ferns. We have used DNA sequences from the low-copy nuclear LFY locus to study an Asplenium polyploid complex. The New Zealand species of this Austral group comprise seven tetraploids and eight octoploids. LFY sequences indicate that allopolyploidy is much more predominant than previously thought, being implicated in the origins of seven of the octoploids. One of the tetraploids has had a central role, being a progenitor for five of the octoploids. All of the octoploids appear to have relatively recent origins, with the dynamic environmental conditions of the Pleistocene possibly playing a role in their formation and/or establishment.     

Context-dependent resistance against butterfly herbivory in a polyploid herb

Spatial variation in biotic interactions and natural selection are fundamental parts of natural systems, and can be driven by differences in both trait distributions and the local environmental context of the interaction. Most studies of plant–animal interactions have been performed only in natural settings, making it difficult to disentangle the effects of traits and context. To assess the relative importance of trait differences and environmental context for among-population variation in plant resistance to herbivory, we compared oviposition by the butterfly Anthocharis cardamines on two ploidy types of the herb Cardamine pratensis under experimentally controlled conditions with oviposition in natural populations. Under controlled conditions, plants from octoploid populations were significantly more preferred than plants from tetraploid populations. This difference was largely mediated by differences in flower size. Among natural populations, there was no difference in oviposition rates between the two ploidy types. Our results suggest that differences in oviposition rates among populations of the two cytotypes in the field are caused mainly by differences in environmental context, and that the higher attractiveness of octoploids to herbivores observed under common environmental conditions is balanced by the fact that they occur in habitats which harbor lower densities of butterflies. This illustrates that spatial variation in biotic interactions is the net result of differences in trait distributions of the interacting organisms and differences in environmental context, and that variation in both traits and context are important in understanding species interactions.     

Linking Genetic Variation in Adaptive Plant Traits to Climate in Tetraploid and Octoploid Basin Wildrye [Leymus cinereus (Scribn. & Merr.) A. Love] in the Western U.S.

Few studies have assessed how ploidy type within a species affects genetic variation among populations in relation to source climates. Basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Love) is a large bunchgrass common in the intermountain Western U.S. found in both octoploid and tetraploid types. In common gardens at two sites over two years differences in both ploidy type and genetic variation within ploidy were observed in phenology, morphology, and production traits on 57 octoploid and 52 tetraploid basin wildrye from the intermountain Western U.S. (P<0.01). Octoploids had larger leaves, longer culms, and greater crown circumference than tetraploids but the numerical ranges of plant traits and their source climates overlapped between ploidy types. Still, among populations octoploids often had greater genetic variation for traits and occupied more diverse climates than tetraploids. Genetic variation for both ploidy types was linked to source climates in canonical correlation analysis, with the first two variates explaining 70% of the variation. Regression of those canonical variates with seed source climate variables produced models that explained 64% and 38% of the variation, respectively, and were used to map 15 seed zones covering 673258 km². Utilization of these seed zones will help ensure restoration with adaptive seed sources for both ploidy types. The link between genetic traits and seed source climates suggests climate driven natural selection and adaptive evolution in basin wildrye. The more diverse climates occupied by octoploids and higher trait variation suggests a higher capacity for ecological differentiation than tetraploids in the intermountain Western U.S.     

Large differences in the composition of herbivore communities and seed damage in diploid and autotetraploid plant species

Herbivory is one of the key interactions affecting plant fitness. Despite the large amount of data available on the effects of herbivores on various plant groups, we still know very little information about the interactions of herbivores with individuals having different ploidy levels. We studied the relationship of diploid and tetraploid Centaurea phrygia in natural and experimental garden conditions to the community of pre‐dispersal seed predators developing in flower heads of the plants. In addition, we collected a set of data on flowering phenology, and flower head morphology and chemistry to investigate potential mechanisms underlying the differences between cytotypes. The two cytotypes are strongly differentiated in their flower head morphology and chemistry as well as in their flowering phenology, with flower heads of diploids being larger, containing more secondary metabolites and flowering later. Also, the two cytotypes strongly differed in the composition of insect communities in the flower heads and tetraploids suffered higher seed damage than the diploids. The differences between cytotypes in seed damage were generally consistent across datasets, indicating that the differences are not due to differences in the habitats in which the cytotypes occur but are due to differences in particular biological characteristics of the plants. The diversity and composition of insect communities, however, strongly varied between years and environments. Flowering phenology could explain part, but not all of the differences observed between cytotypes, indicating that other factors such as flower head morphology or chemistry could also play a role. The study indicated that the differences between the two cytotypes are important determinant of the plant–herbivore interactions in the system. Although we identified multiple factors that could explain the different associations, further research is needed to assess the relative importance of each of these factors. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 115 , 270–287.     

Butterfly seed predation: effects of landscape characteristics,plant ploidy level and population structure

Polyploidization has been suggested as one of the most common mechanisms for plant diversification. It is often associated with changes in several morphological, phenological and ecological plant traits, and therefore has the potential to alter insect–plant interactions. Nevertheless, studies evaluating the effect of plant polyploidy on interspecific interactions are still few. We investigated pre-dispersal seed predation by the butterfly Anthocharis cardamines in 195 populations of two ploidy levels of the herb Cardamine pratensis (tetraploid ssp. pratensis, 2n = 30 vs. octoploid ssp. paludosa, 2n = 56–64). We asked if differences in incidence and intensity of predation among populations were related to landscape characteristics, plant ploidy level and population structure. The incidence of the seed predator increased with increasing plant population size and decreasing distance to nearest population occupied by A. cardamines. The intensity of predation decreased with increasing plant population size and was not affected by isolation. Probability of attack decreased with increasing shading, and intensity of predation was higher in grazed than in non-grazed habitats. The attack intensity increased with increasing mean flower number of plant population, but was not affected by flowering phenology. Individuals in tetraploid populations suffered on average from higher levels of seed predation, had higher mean flower number, were less shaded and occurred more often in grazed habitats than octoploid populations. When accounting for differences in habitat preferences between ploidy levels there was no longer a difference in intensity of predation, suggesting that the observed differences in attack rates among populations of the two ploidy levels are mediated by the habitat. Overall, our results suggest that polyploidization is associated with differentiation in habitat preferences and phenotypic traits leading to differences in interspecific interaction among plant populations. This, in turn, may facilitate further divergence of ploidy levels.     

利用氟乐灵进行同源四倍体萝卜种质创制研究

本研究应用除草剂氟乐灵处理两叶一心幼苗生长点,进行同源四倍体萝卜种质诱导,对变异植株进行形态、细胞学鉴定和花粉母细胞染色体数目鉴定。结果表明,应用 0.2 mmol/L 和 1.0 mmol/L 氟乐灵处理,6个萝卜品种都获得同源四倍体植株,10 mmol/L 处理仅在 Nau-zhqh 得到同源四倍体;其中 0.2 mmol/L处理 Nau-dy 和 1.0 mmol/L 处理 Nau-xbch 获得四倍体最高诱导率(40%);四倍体种质与二倍体种质相比,形态性状、气孔大小、保卫细胞内叶绿体数目、花器官大小、花粉粒大小及花粉萌发率都存在显著差异,将形态、气孔鉴定和染色体计数结合可以准确确定变异株的倍性。研究表明利用氟乐灵诱导是进行萝卜同源四倍体种质创新的有效途径之一。本研究应用除草剂氟乐灵处理两叶一心幼苗生长点,进行同源四倍体萝卜种质诱导,对变异植株进行形态、细胞学鉴定和花粉母细胞染色体数目鉴定。结果表明,应用 0.2 mmol/L 和 1.0 mmol/L 氟乐灵处理,6个萝卜品种都获得同源四倍体植株,10 mmol/L 处理仅在 Nau-zhqh 得到同源四倍体;其中 0.2 mmol/L处理 Nau-dy 和 1.0 mmol/L 处理 Nau-xbch 获得四倍体最高诱导率(40%);四倍体种质与二倍体种质相比,形态性状、气孔大小、保卫细胞内叶绿体数目、花器官大小、花粉粒大小及花粉萌发率都存在显著差异,将形态、气孔鉴定和染色体计数结合可以准确确定变异株的倍性。研究表明利用氟乐灵诱导是进行萝卜同源四倍体种质创新的有效途径之一。     

A cytotaxonomic study of theCalamagrostis purpurea —langsdorffii—canadensis complex in the lowlands of hokkaido

A chromosome survey of 278 individuals from 52 localities confirmed, that the principal components of theCalamagrostis purpurea—langsdorffi—canadensis complex in the lowlands of Hokkaido are tetraploid (2n=28) and octoploid (2n=56). A few hexploids (2n=42), were also found, but they may be either a triploid of the tetraploid plants or a hybrid between the tetraploid and octoploid plants. These hexaploids clearly differ in origin from the North American plants with 2n=42 which are generally placed underC. canadensis. The tetraploids and the octoploids are significantly different in pollen size but resemble each other in other morphological features and ecological requirements. These two races are also not disparate in distribution within Hokkaido. The tetraploids in Hokkaido are closely related to the tetraploids known in Alaska, and these tetraploid plants may be continuously distributed from Hokkaido to Alaska. The octoploids in Hokkaido have shown good pollen. They seem to have had a somewhat different course of evolution fromC. purpurea s. str. which principally reproduces in an apomictic manner.     

Plant polyploidy and host expansion in an insect herbivore

Polyploidization has played an essential role in the diversification of seed plants and often has profound effects on plant physiology and morphology. Yet, little is known about how plant polyploidization has shaped the ecology and evolution of interactions between phytophagous insects and their hosts. Polyploidization could either facilitate or impede colonization of new hosts. Greya politella (Lepidoptera: Prodoxidae) is highly specialized on plants in the genus Lithophragma (Saxifragaceae) throughout most of its geographic range. In central Idaho, some populations have shifted to the related Heuchera grossulariifolia, a plant that has repeatedly undergone autopolyploidization. Previous studies have shown that populations feeding natively on H. grossulariifolia prefer tetraploids to diploids in naturally mixed stands. We investigated whether this difference is caused by an inherent preference for tetraploids, or if the preference in present Heuchera-feeding populations has evolved over time. Moths from a strictly Lithophragma-feeding population were tested for preference of diploid or tetraploid H. grossulariifolia, using a combination of field experiments and caged choice trials. In all trials, attack rates on these non-hosts were very low, with no significant difference between ploidies. In addition, there was little evidence that females manipulated their clutch sizes when ovipositing into different plant species or ploidy levels. Hence, the local shift from Lithophragma to Heuchera in central Idaho is not due to failure of the moths to discriminate between these plant species. Furthermore, the higher attack rates on tetraploids in native H. grossulariifolia-feeding populations cannot be caused by a higher initial preference for these plants, but must instead be a result of differences in plant phenology and/or selection acting on local populations.     

The effects of herbivore-induced plant volatiles on interactions between plants and flower-visiting insects

Plants are faced with a trade-off between on the one hand growth, development and reproduction and on the other hand defence against environmental stresses. Yet, research on insect-plant interactions has addressed plant-pollinator interactions and plant-attacker interactions separately. Plants have evolved a high diversity of constitutive and induced responses to attack, including the systemic emission of herbivore-induced plant volatiles (HIPVs). The effect of HIPVs on the behaviour of carnivorous insects has received ample attention for leaf-feeding (folivorous) species and their parasitoids and predators. Here, we review whether and to what extent HIPVs affect the interaction of plants in the flowering stage with mutualistic and antagonistic insects. Whereas the role of flower volatiles in the interactions between plants and insect pollinators has received increased attention over the last decade, studies addressing both HIPVs and pollinator behaviour are rare, despite the fact that in a number of plant species herbivory is known to affect flower traits, including size, nectar secretion and composition. In addition, folivory and florivory can also result in significant changes in flower volatile emission and in most systems investigated, pollinator visitation decreased, although exceptions have been found. Negative effects of HIPVs on pollinator visitation rates likely exert negative selection pressure on HIPV emission. The systemic nature of herbivore-induced plant responses and the behavioural responses of antagonistic and mutualistic insects, requires the study of volatile emission of entire plants in the flowering stage. We conclude that approaches to integrate the study of plant defences and pollination are essential to advance plant biology, in particular in the context of the trade-off between defence and growth/reproduction.     

Phytogeographical studies ofCalamagrostis sachalinensis (Gramineae)

Chromosome numbers were determined on 223 collections ofCalamagrostis sachalinensis from 18 localities in Japan. The plants were found to be tetraploid (2n=28), hexaploid (2n=42) or octoploid (2n=56). A few collections were found to include one or two B-chromosomes. The tetraploid collections were made from central Honshu and Mt. Apoi in Hokkaido, while the hexaploids and the octoploids were detected in many localities. Pollen examination of these collections showed that the tetraploids with but one exception have good pollen and the hexaploids and the octoploids have no pollen or have bad pollen with stainability less than 10%. With the help of pollen examination of a number of herbarium specimens, the distribution of the tetraploids and that of the assemblage of the hexaploids and octoploids were delineated. Morphological studies indicated that the tetraploid, hexaploid and octoploid plants can not be separated in gross and spikelet morphology and that the tetraploids in central Honshu and those in Mt. Apoi are significantly different in leaf features. It was concluded thatC. sachalinensis represents an apo-amphimictic complex, which includes the following four races: 1) tetraploid, amphimictic, having thin leaf blades 5–10 mm broad and growing on the subalpine conifer forest belt and the conifer forest-alpine ecotone in the mountains of central Honshu; 2) tetraploid, amphimictic, having hard leaf blades 2–6 mm broad and growing on the stony, arid and exposed alpine belt on Mt. Apoi in Hokkaido; 3) hexaploid, mainly apomictic, the most variable ecologically, widely distributed; 4) octoploid, mainly apomictic, frequent in the upper montane to alpine belts, probably widely distributed.     

Plant Size as Determinant of Species Richness of Herbivores,Natural Enemies and Pollinators across 21 Brassicaceae Species

Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground), the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness). We found a lower R² for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their natural enemies, whether they are endophagous or ectophagous or associated with leaves or fruits.     

Anther-smut infection of Silene alba caused by Ustilago violacea: factors determining fungal reproduction

Summary The anther-smut fungus Ustilago violacea sporulates in flowers of the dioecious host plant Silene alba. Growth chamber comparisons of healthy and diseased plants, with the genetic background of host and pathogen controlled, revealed that fungal infection increases the number of flowers produced per plant and decreases the size of individual flowers. There were few consistent effects of plant genotype or fungal isolate on diseased flower traits, but differences between the plant sexes were apparent. Stimulation of flower production is proportionally greater in females than males: thus, although healthy male plants produce many more flowers than healthy females, sexual differences in diseased flower number are reduced. Sexual differences in diseased flower size also exist, with male flowers smaller than females. A field inoculation study confirmed dimorphism in diseased flower size and demonstrated that spore production per flower was greater for males than females for all flower size classes.     

Adaptive Sex‐Specific Cognitive Bias in Predation Behaviours of Japanese Pygmy Squid

Errors in decision‐making in animals can be partially explained by adaptive evolution, and error management theory explains that cognitive biases result from the asymmetric costs of false‐positive and false‐negative errors. Error rates that result from the cognitive bias may differ between sexes. In addition, females are expected to have higher feeding rates than males because of the high energy requirements of gamete production. Thus, females may suffer relatively larger costs from false‐negative errors (i.e. non‐feeding) than males, and female decisions would be biased to reduce these costs if the costs of false‐positive errors are not as high. Females would consequently overestimate their capacity in relation to the probability of predation success. We tested this hypothesis using the Japanese pygmy squid Idiosepius paradoxus. Our results show that size differences between the squid and prey shrimp affected predatory attacks, and that predatory attacks succeeded more often when the predator was relatively larger than the prey. Nevertheless, compared to male predatory attacks, female squid frequently attacked even if their size was relatively small compared to the prey, suggesting that the females overestimated their probability of success. However, if the females failed in the first attack, they subsequently adjusted their attack threshold: squid did not attack again if the prey size was relatively larger. These results suggest a sex‐specific cognitive bias, that is females skewed judgment in decision‐making for the first predation attack, but they also show that squid can modify their threshold to determine whether they should attack in subsequent encounters.     

Spontaneous tetraploidy in apomictic seedlings ofCitrus

Populations of apomictic seedlings of clones ofCitrus species,Citrus hybrids, andPoncirus in the sub-family Aurantioideae were examined for spontaneous tetraploids as a source of materials for use in breeding experiments. Diagnostic features found useful in identifying nucellar tetraploids were leaf shape, petiole blade shape, leaf blade thickness, leaf color, comparative size differences in leaf venation, oil glands, and stomata, stem thickness, and relative size and developmental pattern of the root system. In older or bearing-age plants, nucellar tetraploids may be identified by differences in growth habit, vigor, size, time of growth initiation and bloom, and flower and fruit characteristics. Data are given for tetraploid frequency in glasshouse-grown, first-year nucellar seedlings of 42 populations of 32 clones of different genetic and seed origin and for tetraploid frequency in commercialnursery nucellar seedlings of the Carrizo rootstock clone in two consecutive years. Comparative data are given for quantitative development of roots, stems, and leaves of tetraploids and similar diploid nucellar seedlings. The data suggest that the ability to produce tetraploid apomictic seedlings is a variable genetic trait present in all or nearly all clones able to reproduce by adventitious embryony. Aspects of tetraploid nucellar seedlings that might warrant their testing as tree-size-controlling rootstocks in commercial citrus growing are discussed.     

Plant polyploidy and insect/plant interactions

We used flow cytometry and extensive geographic surveys of herbivore attack to test whether repeated evolution of autotetraploidy in the perennial herb Heuchera grossulariifolia Rydb. (Saxifragaceae) has created evolutionary barriers to attack by the specialist moth herbivore Greya politella (Prodoxidae). We found that the moth has colonized tetraploid as well as diploid populations, has colonized tetraploids of separate evolutionary origin, and, at least under some conditions, is more likely to attack tetraploids than diploids. Plant polyploidy therefore provides a potential route out of specialization as an evolutionary dead end in phytophagous insect taxa as well as a potentially important route to subsequent phylogenetic and geographic diversification of plant/insect interactions.     

The contribution of a pollinating seed predator to selection on Silene latifolia females

Interactions, antagonistic or mutualistic, can exert selection on plant traits. We explored the role of Hadena bicruris, a pollinating seed predator, as a selective agent on its host, the dioecious plant Silene latifolia. We exposed females from artificial-selection lines (many, small flowers (SF) vs. few, large flowers (LF)) to this moth. Infestation did not differ significantly between lines, but the odds of attacked fruits aborting were higher in SF females. We partitioned selection between that caused by moth attack and that resulting from all other factors. In both lines, selection via moth attack for fewer, smaller flowers contrasted with selection via other factors for more flowers. In LF females, selection via the two components was strongest and selection via moth attack also favoured increased fruit abortion. This suggests that the moths act as more of a selective force on flower size and number via their predating than their pollinating role.     

Induced polyploidization and its influence on yield,morphological, and qualitative characteristics of microtubers in <Emphasis Type="Italic">Ullucus tuberosus</Emphasis>

This study aimed to induce in vitro polyploidization in diploid ulluco (2n = 24) using oryzalin, an antimicrotubule agent. Nodal segments were treated with 0, 20, 25 or 30 μM oryzalin for 24 or 48 h. Ploidy determination of regenerants was based on flow cytometry and chromosome countings in metaphasic cells from root tips. After polyploidization, microtuber formation was induced in plantlets. Determination of starch content using spectrophotometric analysis, and vitamin C content by titration with 2,6-dichlorphenolindophenol were carried out to assess diploid and octoploid microtubers. Colour of in vitro plantlets was evaluated using the RHS colour chart. Out of 120 nodal segments exposed to oryzalin, 2.5% were octoploids (2n = 96). The most efficient conditions for inducing polyploidy were treatment with 20 μM oryzalin for 24 h, followed by 25 μM oryzalin for 48 h. No tetraploids were obtained. Moreover, flow cytometric analyses of the nuclear DNA contents revealed extensive endopolyploidy in both diploids and octoploids. Morphological differences of the octoploids compared to diploids included lower plantlet height, significantly thicker stems and shorter and darker leaves. Although the average weight of octoploid microtubers was lower compared to diploid ones, they were rich in vitamin C and they had lower starch content. These preliminary results indicate that octoploids may be used in further breeding efforts to obtain low-starch ulluco varieties with improved antioxidant properties.