Evaluation of Wheat Chromosome Translocation Lines for High Temperature Stress Tolerance at Grain Filling Stage

High temperature (HT, heat) stress is detrimental to wheat (Triticum aestivum L.) production. Wild relatives of bread wheat may offer sources of HT stress tolerance genes because they grow in stressed habitats. Wheat chromosome translocation lines, produced by introgressing small segments of chromosome from wild relatives to bread wheat, were evaluated for tolerance to HT stress during the grain filling stage. Sixteen translocation lines and four wheat cultivars were grown at optimum temperature (OT) of 22/14°C (day/night). Ten days after anthesis, half of the plants were exposed to HT stress of 34/26°C for 16 d, and other half remained at OT. Results showed that HT stress decreased grain yield by 43% compared with OT. Decrease in individual grain weight (by 44%) was the main reason for yield decline at HT. High temperature stress had adverse effects on leaf chlorophyll content and Fv/Fm; and a significant decrease in Fv/Fm was associated with a decline in individual grain weight. Based on the heat response (heat susceptibility indices, HSIs) of physiological and yield traits to each other and to yield HSI, TA5594, TA5617, and TA5088 were highly tolerant and TA5637 and TA5640 were highly susceptible to HT stress. Our results suggest that change in Fv/Fm is a highly useful trait in screening genotypes for HT stress tolerance. This study showed that there is genetic variability among wheat chromosome translocation lines for HT stress tolerance at the grain filling stage and we suggest further screening of a larger set of translocation lines.     

Assessment of terminal heat tolerance ability of wheat genotypes based on physiological traits using multivariate analysis

Terminal heat stress is one of the limiting factors in wheat production and it is expected to rise under present scenario of climate change. The present study was conducted to evaluate the performance of 40 wheat genotypes under terminal heat stress conditions based on eight physiological traits. The plants were sown late (i.e. on 5th January) to expose them terminal heat stress. The genotypes were evaluated using multivariate analysis viz. Ward’s method of hierarchical clusters analysis, discriminant analysis and principle component analysis. The genotypes were categorized into three groups namely tolerant, intermediate and sensitive. Tolerant genotypes like DBW 14, RAJ 3765, HD 2643 and HALNA performed physiologically better in terms of higher membrane stability index (MSI), chlorophyll content, photosynthesis rate (Pn), harvest index under heat stress conditions. Genotypes HD 2987, SHANGHAI, HD 2402 and WH 730 were found to be heat sensitive. Physiological traits like MSI, SPAD value, Fv/Fm ratio and Pn were found to be most important contributor in grouping of genotypes and showed positive correlations (r) of 0.73, 0.47, 0.41 and 0.39 with grain yield, respectively, which is significant at p < 0.05. The large genetic diversity was found among the genotypes based on physiological traits. These genotypes can be utilized in wheat improvement programme for heat tolerance.     

有棱丝瓜苗期耐热性及其对热胁迫的生理响应

为鉴定有棱丝瓜(Luffa acutangula)的耐热性,对32个品种进行了耐热性筛选,并对不同耐热性品种在热胁迫下的生理响应进行了研究。结果表明,这些品种中有耐热品种3个,热敏品种4个,居中的25个。对耐热品种WB121,较耐热品种YL8和热敏品种WB105进行高温处理,结果表明,随着高温胁迫时间的延长,3个品种叶片的丙二醛含量、相对电导率、可溶性糖含量均逐渐增加。3种保护酶(SOD、CAT和POD)活性未表现出与耐热性一致的变化。3个品种的叶绿素荧光参数Fv/Fm、Yeild和ETR随着高温胁迫时间的延长均下降,以热敏品种下降幅度最大。Pearson相关分析表明,热害指数与相对电导率呈显著正相关(r=0.693*),与丙二醛和可溶性糖含量呈极显著正相关(r=0.814,0.899**),与叶绿素荧光参数(Fv/Fm,Yield,ETR)呈极显著负相关(r=-0.892,-0.896,-0.897**),与3种保护酶活性的相关性不显著。由此可见,叶绿素荧光参数(Fv/Fm,Yield,ETR)可以快速、准确地反映植物热害,建议将其作为有棱丝瓜耐热性鉴定的重要生理指标。     

Comparative physiological response of wheat genotypes under terminal heat stress

Wheat (Triticum aestivum L.), a staple food crop, is of great commercial importance. Its production is restricted due to multiple environmental stresses. There are indications that the wheat production is consistently limited by terminal heat stress. Previous studies revealed a varied response of different wheat genotypes under heat stress conditions. Here, comparative physiological changes in wheat genotypes viz., DBW-140, Raj-3765, PBW-574, K-0-307 and HS-240 were evaluated under timely and late sown conditions in rabi season. We observed that heat stress dramatically affects chlorophyll content and leaf area index (LAI) in sensitive genotypes whereas proline and malondialdehyde (MDA) content were higher in tolerant genotypes under late sown conditions. Further, the heat susceptibility index (HIS) for 1,000-grain weight, grain weight and grain yield of wheat genotypes viz., HS 240 and K-0-307 was highest as compared with DBW 140, Raj 3765 and PBW 574 genotypes. This finding suggests that wheat genotypes are found to differ in their ability to respond to heat, thereby tolerance, which could be useful as genetic stock to develop wheat tolerant varieties in breeding programs.     

外源甜菜碱对盐胁迫下枸杞光合功能的改善

研究了外源甜菜碱对盐胁迫下枸杞扦插苗叶片光合功能的影响。结果表明,外源甜菜碱能使盐胁迫下的枸杞叶片叶绿素荧光动力学参数Fo、Fm、Fv、Fv／Fm、Fm／Fo和Fv／Fo增高,使光合色素叶绿素a(Chla)、叶绿素b(Chlb)和类胡萝卜素(Car)含量明显增加,叶绿素a与b的比值(Chla／Chlb)升高,类胡萝卜素与叶绿素的比值(Car／Chl)降低,说明外源甜菜碱有利于植物对光能的捕获、吸收、传递和转换,提高叶片的光合活性,降低盐胁迫对植物的抑制作用。     

弱光胁迫对玉米产量及光合特性的影响

通过在玉米授粉前0～14d、授粉后1～14d、授粉后15～28d3个时期分别进行遮光处理,研究了弱光胁迫对两个玉米品种费玉3号和泰玉2号产量及光合特性的影响.结果表明:各时期弱光胁迫均使玉米产量降低,其中授粉前0～14d弱光处理的产量降幅最大,费玉3号对弱光胁迫的反应较泰玉2号敏感.弱光胁迫后籽粒灌浆高峰出现时间延迟、灌浆速率慢、积累量小;弱光胁迫开始的时间越早,籽粒达到最大灌浆速率的时间(Tmax)越晚.弱光胁迫期内,玉米Chl(a b)、Chla/b、光合速率(Pn)、光系统Ⅱ最大光化学效率(Fv/Fm)和光系统Ⅱ实际光化学效率(ФPSⅡ)显著下降,Chlb相对含量提高,胞间二氧化碳浓度(Ci)和非光化学淬灭系数(NPQ)则显著上升;胁迫结束后,玉米Chl(a b)、Chla/b、Pn、Fv/Fm、ФPSⅡ、Ci和NPQ逐渐恢复接近自然光照条件(CK)水平,而Chlb相对含量下降.表明非气孔因素是弱光胁迫下玉米光合速率降低的原因之一.     

Effects of benzyladenine and abscisic acid on the disassembly process of photosystems in anArabidopsis delayed-senescence mutant,ore9

Using wild-type (WT) leaves and those from anore9 delayed-senescenceArabidopsis mutant, we investigated the delaying and accelerating effects of benzyladenine (BA) and abscisic acid (ABA), respectively, on the degradation process of the photosynthetic apparatus during dark-induced senescence (DIS). In the mutant, delays were seen for both the breakdown of chlorophyll (Chl) and the decrease in photochemical efficiency of photosystem II (Fv/Fm). Moreover, each step was prolonged in the disassembly process of the Chl-protein complexes. In the presence of BA, Chl degradation was retarded to a similar extent for both the mutant and the WT, but the decrease in Fv/Fm was not. However, in the presence of ABA, the two processes were accelerated in both genotypes. Therefore, although theore9 mutation causes this functional delayed-senescence, it may not be related to the non-functional delay that happens afterwards. In contrast, BA seems to affect both processes.     

Intra- specific variation in response of Jatropha (Jatropha curcas L.) to elevated CO2 conditions

Twenty genotypes of Jatropha collected from diverse eco-geographic regions from the states of Chhattisgarh (3), Andhra Pradesh (12), Rajasthan (4) and Uttarakhand (1) of India were subjected to elevated CO₂ conditions. All the genotypes showed significant difference (p < 0.05 and 0.01) in the phenotypic traits in both the environments (elevated and ambient) and genotype x environment interaction. Among the physiological traits recorded, maximum photosynthetic rate was observed in IC565048 (48.8 μmol m⁻² s⁻¹) under ambient controlled conditions while under elevated conditions maximum photosynthetic rate was observed in IC544678 (41.3 μmol m⁻² s⁻¹), and there was no significant difference in the genotype x environment interaction. Stomatal conductance (Gs) emerged as the key factor as it recorded significant difference among the genotypes, between the environments and also genotype x environment interaction. The Gs and transpiration (E) recorded a significant decline in the genotypes under the elevated CO₂ condition over the ambient control. Under elevated CO₂ conditions, the minimum values recorded for Gs and E were 0.03 mmol m⁻² s⁻¹ and 0.59 mmol m⁻² s⁻¹ respectively in accession IC565039, while the maximum values for Gs and E were 1.8 mmol m⁻² s⁻¹ and 11.5 mmol m⁻² s⁻¹ as recorded in accession IC544678. The study resulted in the identification of potential climate ready genotypes viz. IC471314, IC544654, IC541634, IC544313, and IC471333 for future use.     

Light Affects the Chloroplast Ultrastructure and Post-Storage Photosynthetic Performance of Watermelon (Citrullus lanatus) Plug Seedlings

Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] plug seedlings were stored at 15°C in the light at a photosynthetic photon flux density of 15 µmol·m⁻²·s⁻¹ or in darkness for 6 days, to evaluate their chloroplast ultrastructure, and associated photosynthetic characteristics. Storage in the dark caused swelling, disordered granal arrangement, and starch grain disappearance in the chloroplasts. In contrast, the chloroplasts stored in the light were relatively normal. As a result, the light-stored seedlings had a significantly higher chlorophyll content, Fv/Fm, and Pn than did dark-stored seedlings. Regardless of whether the seedlings were stored in light or darkness, the Gs and Ls of the seedlings significantly decreased, while the Ci obviously increased when the Pn decreased after 6 days of storage. This result suggests that the decreased Pn is not solely a stomatal effect, as the effects on the chloroplasts contributed to this photosynthetic inhibition. Six days after transplanting, seedlings that were stored in the light or darkness for 2 or 4 days showed complete recovery of chloroplast ultrastructure, chlorophyll content, Fv/Fm, Gs and Pn. When the storage period increased to 6 days, the dark-stored seedlings had a significantly lower Fv/Fm and Pn than the light-stored and control seedlings 6 days after transplanting, which was mainly ascribed to incomplete recovery of chloroplast ultrastructure. Furthermore, the light-stored seedlings exhibited a significantly higher shoot dry weight during storage and a higher percentage dry weight increase after transplanting than the dark-stored seedlings. These effects were enhanced by prolonged storage (4 to 6 days). This study demonstrated that dim light during storage is beneficial for maintaining chloroplast ultrastructure as well as photosynthetic efficiency in watermelon seedlings, thus contributing to the rapid recovery of post-storage photosynthetic performance, which ensures the transplant quality of the seedlings after removal from storage.     

Ocular blood flow decreases during passive heat stress in resting humans

Background

Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow.

Findings

Ocular blood flow, end-tidal carbon dioxide (P_ETCO₂) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35°C (normothermia) for 30 min and (2) at 50°C for 90 min (passive heat stress). The blood-flow velocities in the superior temporal retinal arteriole (STRA), superior nasal retinal arteriole (SNRA), and the retinal and choroidal vessels (RCV) were measured using laser-speckle flowgraphy. Blood flow in the STRA and SNRA was calculated from the integral of a cross-sectional map of blood velocity. P_ETCO₂ was clamped at the normothermia level by adding 5% CO₂ to the inspired gas. Passive heat stress had no effect on the subjects’ blood pressures. The blood-flow velocity in the RCV was significantly lower after 30, 60 and 90 min of passive heat stress than the normothermic level, with a peak decrease of 18 ± 3% (mean ± SE) at 90 min. Blood flow in the STRA and SNRA decreased significantly after 90 min of passive heat stress conditions, with peak decreases of 14 ± 3% and 14 ± 4%, respectively.

Conclusion

The findings of this study suggest that passive heat stress decreases ocular blood flow irrespective of the blood pressure or arterial partial pressure of CO₂.     

Physiological and biochemical response of different resistant alfalfa cultivars against thrips damage

To investigate physiological and biochemical changes of thrips-resistant alfalfa (Medicago sativa L. cv. Gan-nong No. 9), we aimed at clarifying the response mechanisms of alfalfa against thrips. Medicago sativa L. cv. including thrips-resistant Gan-nong No.9 (G9), thrips-susceptible Gan-nong No.3 (G3) and highly thrips-susceptible WL363HQ (363) were infested with different thrips densities (3, 5, 7 and 9-thrips per branch). The quantitative change in specific nutrients, secondary metabolites, defensive and antioxidant enzymes were measured at seedling stage of the three alfalfa cultivars. The results showed that with the increase of thrips densities, the damage indices, SS, Pro, flavonoids, tannin and H₂O₂ in G9, G3 and 363 were significantly increased, but PPO and SOD significantly reduced, compared with CK. Furthermore, the tannin and lignin contents of G9 were significantly higher compared to 363, but SP content was significantly lower than G3 and H₂O₂ content which was further significantly less compared to 363. Correlation analysis observed that the damage index of the three alfalfa cultivars showed a significant positive association with SS, Pro, flavone, tannin, and H₂O₂ (P < 0.01), while damage index and DW, Chl (a, b, a + b), PPO and SOD showed a significant negative correlation (P < 0.01). Based on principal component comprehensive evaluation, the 5-thrips adults per branch were the critical inoculation threshold for G9 against thrips injury because the score was – 0.048. These results revealed that thrips damage significantly increased the contents of SS, Pro, flavonoids, tannins and H₂O₂, as well as significantly declined the activities of PPO and SOD in the three cultivars (P < 0.05), moreover, thrips-resistant G9 markedly accumulated lignin content, POD and CAT activity, inhibited Chl (a + b, b) and SP biosynthesis to resist thrips damage.     

水分胁迫对牛心朴子叶片光合色素及叶绿素荧光的影响

研究了水分胁迫对牛心朴子叶片光合色素及叶绿素荧光动力学参数的影响。结果表明,在长期的水分胁迫中,牛心朴子叶片的叶绿素a(Chl a)、叶绿素b(Chl b)和类胡萝卜素(Car)含量没有下降或下降不明显。直到处理末期才显著下降;叶片叶绿素荧光动力学参数Fo、Fm、Fv、Fv／Fm变化不大,在处理末期各处理Fo降低,轻度、重度水分胁迫的Fm、Fv、Fv／Fm升高。说明K期水分胁迫后牛心朴子的光合功能受到影响,但牛心朴子仍表现出较强的适应干旱的能力。     

Effects of Strong Light and Active Oxygen on Photosynthesis in Soybean

With the use of chlorophyll fluorescence technique, it was found that the net photosynthetic oxygen evolution rate decreased after strong light (2 000 μmol· m-2·2-1 ) treatment for two hours in soybean ( Glycine max L. ) leaves. The chlorophyll fluorescence parameters, Fm/Fo, Fv/Fm, ФPSII, qp and qN decreased along with the increase of light intensity. In strong light, exogenous active oxygen H202、·OH and 'O2 were harmful to soybean leaves. The destruction of 'O2 and·OH to leaves was most evident, as was shown that Fv/Fm and PS H decreased significantly. The antioxidants DABCO, mannitol, ascorbate and histidine protected the leaves, but weakly, from strong light. In darkness, the SOD inhibitor sodium diethyldithiocar- bamate (DDC) had no significant effect on Fm/Fo and Fv/Fm, but NAN,, the ascorbate peroxidase (APX)inhibitor, significantly decreased Fm/Fo, Fv/Fm and ФPS II. In strong light, however, beth DDC and NaN3 reduced the above-mentioned fluorescence parameters, but NaN3 was more effective than DDC. The results suggested that photoinhibition did take place in soybean leaves under strong light, and it was related to active oxygen in vivo.     

Effects of Epiphytic Load on the Photosynthetic Performance of a Seagrass, <Emphasis Type="Italic">Zostera marina</Emphasis>, Monitored In Vivo by Chlorophyll Fluorescence Imaging

We investigated the effects of epiphytes on photosynthetic activity in a seagrass, Zostera marina. Parameters in our chlorophyll (Chl) fluorescence imaging technique, including Fo, Fm, and Fv/Fm, were monitored from leaf surfaces before and after those epiphytes were removed. Because of the uneven distribution of light intensities, Fm values at the margin of an image were underestimated while those in the central region were overestimated. Chl fluorescence emissions from all leaves except the youngest one were altered by the presence of epiphytes, which predominantly inhabited the surfaces of older leaves. Only a few were found lower on the plant where leaves were very close to each other. Regions where the epiphytes had been loosely bound before their gentle removal showed full restoration of photosynthetic performance to control levels afterward. However, only minor recovery of photosynthesis was found in areas that had been riddled with tightly bound epiphytes and were permanently damaged. In years 2002 and 2003, leaf productivity peaked in May and plummeted in November. More epiphytic diatoms were distributed when the seagrass biomass was larger, with pinnate diatoms dominating.     

Morpho-physiological and molecular characterization of drought tolerance traits in Gossypium hirsutum genotypes under drought stress

Drought stress is one of the major abiotic stresses affecting lint yield and fibre quality in cotton. With increase in population, degrading natural resources and frequent drought occurrences, development of high yielding, drought tolerant cotton cultivars is critical for sustainable cotton production across countries. Six Gossypium hirsutum genotypes identified for drought tolerance, wider adaptability and better fibre quality traits were characterized for various morpho-physiological and biochemical characters and their molecular basis was investigated under drought stress. Under drought conditions, genotypes revealed statistically significant differences for all the morpho-physiological and biochemical traits. The interaction (genotype × treatment) effects were highly significant for root length, excised leaf water loss and cell membrane thermostability indicating differential interaction of genotypes under control and stress conditions. Correlation studies revealed that under drought stress, relative water content had significant positive correlation with root length and root-to-shoot ratio while it had significant negative correlation with excised leaf water loss, epicuticular wax, proline, potassium and total soluble sugar content. Analysis of expression of fourteen drought stress related genes under water stress indicated that both ABA dependent and ABA independent mechanisms of drought tolerance might be operating differentially in the studied genotypes. IC325280 and LRA5166 exhibited ABA mediated expression of stress responsive genes and traits. Molecular basis of drought tolerance in IC357406, Suraj, IC259637 and CNH 28I genotypes could be attributed to ABA independent pathway. Based on physiological phenotyping, the genotypes IC325280 and IC357406 were identified to possess better root traits and LRA5166 was found to have enhanced cellular level tolerance. Variety Suraj exhibited good osmotic adjustment and better root traits to withstand water stress. The identified drought component trait(s) in specific genotypes would pave way for their pyramiding through marker assisted cotton breeding.Electronic supplementary materialThe online version of this article (10.1007/s12298-020-00890-3) contains supplementary material, which is available to authorized users.     

In vitro development of microcorms and stigma like structures in saffron (Crocus sativus L.)

Saffron is an important spice derived from the stigmas of Crocus sativus, a species belonging to the family Iridaceae. Due to its triploid nature it is sterile and is not able to set seeds, so it is propagated only by corms. The natural propagation rate of most geophytes including saffron is relatively low. An in vitro multiplication technique like micropropagation has been used for the propagation of saffron. In the present study, various explants were cultured on different nutrient media supplemented with various concentrations of plant growth regulators to standardize the best media combination for obtaining optimum response with respect to corm production and development of Stigma Like Structures (SLS). Highest response (60 %) was observed with half ovaries on G-5 media supplemented with 27 μM NAA and 44.4 μM BA followed by 55 % on LS media with 27 μM NAA and 44.4 μM BA. Maximum size (1.3 g) of microcorms were obtained from apical buds on the LS media supplemented with 21.6 μM NAA and 22.2 μM. Stigma Like Structures were developed from half ovary explants both directly and indirectly. Maximum number (120 indirectly and 20 directly) and size (5.2 cm) of SLS were obtained in G-5 medium supplemented with 27 μM NAA and 44.4 μM BA followed by 100 indirectly and 20 directly and 4.5 cm long on LS medium supplemented with 27 μM NAA and 44.4 μM BA.     

NPR1-dependent salicylic acid signaling is not involved in elevated CO2-induced heat stress tolerance in Arabidopsis thaliana

Elevated CO₂ can protect plants from heat stress (HS); however, the underlying mechanisms are largely unknown. Here, we used a set of Arabidopsis mutants such as salicylic acid (SA) signaling mutants nonexpressor of pathogenesis-related gene 1 (npr1-1 and npr1-5) and heat-shock proteins (HSPs) mutants (hsp21 and hsp70-1) to understand the requirement of SA signaling and HSPs in elevated CO₂-induced HS tolerance. Under ambient CO₂ (380 µmol mol⁻¹) conditions, HS (42°C, 24 h) drastically decreased maximum photochemical efficiency of PSII (Fv/Fm) in all studied plant groups. Enrichment of CO₂ (800 µmol mol⁻¹) with HS remarkably increased the Fv/Fm value in all plant groups except hsp70-1, indicating that NPR1-dependent SA signaling is not involved in the elevated CO₂-induced HS tolerance. These results also suggest an essentiality of HSP70-1, but not HSP21 in elevated CO₂-induced HS mitigation.     

Temperature transcends partner specificity in the symbiosis establishment of a cnidarian

Coral reef research has predominantly focused on the effect of temperature on the breakdown of coral-dinoflagellate symbioses. However, less is known about how increasing temperature affects the establishment of new coral-dinoflagellate associations. Inter-partner specificity and environment-dependent colonization are two constraints proposed to limit the acquisition of more heat tolerant symbionts. Here, we investigated the symbiotic dynamics of various photosymbionts in different host genotypes under “optimal” and elevated temperature conditions. To do this, we inoculated symbiont-free polyps of the sea anemone Exaiptasia pallida originating from Hawaii (H2), North Carolina (CC7), and the Red Sea (RS) with the same mixture of native symbiont strains (Breviolum minutum, Symbiodinium linucheae, S. microadriaticum, and a Breviolum type from the Red Sea) at 25 and 32 °C, and assessed their ITS2 composition, colonization rates, and PSII photochemical efficiency (Fv/Fm). Symbiont communities across thermal conditions differed significantly for all hosts, suggesting that temperature rather than partner specificity had a stronger effect on symbiosis establishment. Overall, we detected higher abundances of more heat resistant Symbiodiniaceae types in the 32 °C treatments. Our data further showed that PSII photophysiology under elevated temperature improved with thermal pre-exposure (i.e., higher Fv/Fm), yet, this effect depended on host genotype and was influenced by active feeding as photochemical efficiency dropped in response to food deprivation. These findings highlight the role of temperature and partner fidelity in the establishment and performance of symbiosis and demonstrate the importance of heterotrophy for symbiotic cnidarians to endure and recover from stress.Subject terms: Climate-change ecology, Animal physiology     

Sexual dimorphism in digital dermatoglyphic traits among Sinhalese people in Sri Lanka

Background

The purpose of this study was to evaluate gender-wise diversity of digital dermatoglyphic traits in a sample of Sinhalese people in Sri Lanka.

Findings

Four thousand and thirty-four digital prints of 434 Sinhalese individuals (217 males and 217 females) were examined for their digital dermatoglyphic pattern distribution. The mean age for the entire group was 23.66 years (standard deviation = 4.93 years). The loop pattern is observed more frequently (n = 2,592, 59.72%) compared to whorl (n = 1,542, 35.53%) and arch (n = 206, 4.75%) in the Sinhalese population. Females (n = 1,274, 58.71%) have a more ulnar loop pattern than males (n = 1,231, 56.73%). The plain whorl pattern is observed more frequently in males (n = 560, 25.81%) compared to females (n = 514, 23.69%).The double loop pattern is observed more frequently on the right and left thumb (digit 1) of both males and females. Pattern intensity index, Dankmeijer index and Furuhata index are higher in males.

Conclusions

Ulnar loop is the most frequently occurring digital dermatoglyphic pattern among the Sinhalese. All pattern indices are higher in males. To some extent, dermatoglyphic patterns of Sinhalese are similar to North Indians and other Caucasoid populations. Further studies with larger sample sizes are recommended to confirm our findings.