Number Of Capitula Research Articles

Physiological Indices for the Selection of Drought-Tolerant Safflower Genotypes for Cultivation in Marginal Areas

Safflower is known as a tolerant plant to abiotic stress factors. This study was conducted to introduce some physiological indices to improve drought-tolerant safflower genotypes for cultivation in marginal and arid areas. Six safflower genotypes were studied for two years (2017–2019) in the East Azarbaijan Agricultural and Natural Resources Research and Education Centre of Iran under non-stressed and low-water conditions from flowering to seed maturity. The occurrence of water deficits led to a significant decrease in relative water content (RWC), stomatal conductance (gs), osmotic adjustment (Oadj), water potential (WP) and agronomic water use efficiency (WUEa) and an increase in the water stress index (CWSI). In addition, the values of these traits differed significantly between the safflower genotypes. The correlations between the physiological traits and seed yield were significant. The regression relationships between seed yield and the above traits showed that CWSI, WP and WUEa had a strong relationship with seed yield under normal (R2 = 0.854, 0.801 and 0.856, respectively) and water deficit conditions (R2 = 0.931, 0.877 and 0.900, respectively). It can be concluded that the CWSI, WP and WUEa indices are able to select high-yielding and drought-tolerant safflower genotypes for the late season. Among the components of seed yield, the number of capitula per plant (r = 0.86) and seeds per capitula (r = 0.92), which were positively and significantly correlated with seed yield, played the main roles in the formation of seed yield. The Golemehr and Mec.295 genotypes achieved higher seed yields under normal (4676 and 4961 kg h−1, respectively) and water deficit conditions (3211 and 3385 kg h−1, respectively) and can be recommended for cultivation in marginal and arid areas.

Glyphosate hormesis effects on the vegetative and reproductive development of glyphosate-susceptible and -resistant Conyza sumatrensis biotypes

Low glyphosate doses that produce hormesis may alter the susceptibility to herbicides of weeds or enhance their propagation and dispersal. The objective of this work was to evaluate the hormetic effects of glyphosate on the vegetative, phenological and reproductive development in resistant (R) and susceptible (S) Conyza sumatrensis biotypes. The glyphosate resistance level of biotype R was 11.2-fold compared to the S biotype. Glyphosate doses <11.25 g ae ha−1 induced temporary and permanent hormetic effects for the number of leaves, plant height and dry mass accumulation up to 28 d after application in both R and S biotypes. The S biotype required 15–19% fewer thermal units at 1.4 and 2.8 g ae ha−1 glyphosate than untreated plants to reach the bolting stage. Also, this biotype had less thermal units associated with the appearance (1225 vs 1408 units) and opening (1520 vs 1765 units) of the first capitulum than the R biotype. In addition, glyphosate affected reproductive traits of both biotypes compared to their controls, increasing the number of capitulum's and seeds per plant up to 37 and 41% (at 2.8 and 0.7 g ae h−1, respectively) in the S biotype, and by 48 and 114% (both at 5.6 g ae ha−1) in the R biotype. Depending on environmental parameters, glyphosate may or may not cause hormetic effects on the vegetative and phenological development of C. sumatrenis biotypes; however, this herbicide increases the speed and fecundity of reproduction, regardless of the glyphosate susceptibility level, which can alter the population dynamics and glyphosate susceptibility of future generations.

Genetic variability and heritability of seed yield and yield contributing characters in safflower (Carthamus tinctorius L.)

In the present study, genotypic and phenotypic variability were worked out on 34 genotypes of safflower for yield and yield contributing characters at Department of Genetics and Plant breeding at Sam Higginbottom University of Agriculture, Technology, and Sciences in Prayagraj during rabi 2021. The experiment was conducted by using RBD design with three replications. The information was compiled using 12 characters to examine the genotypes of safflower with regard to genetic variability, heritability, the connection of yield contributing components with yield The highest percentage of PCV (64.93 ), GCV (65.26) and heritability (99% ) were found for number of Capitulum per plant. Low heritability estimates were found for the seed index and capitulum diameter whereas moderate genetic gain was seen for capitulum diameter, days to maturity, days to 50% flowering, and plant height. When a trait is highly heritable and genetic progress as a percentage of the mean, it is likely that additive gene action, with equal contributions from non-additive and additive gene action, is responsible for the trait.

In-vitro Induction of Polyploidy in Niger (Guizotia abyssinica L.f. Cass) through Colchicine Treatment

The present study was conducted to induce polyploidy through colchicine treatment to obtain better yield by enhancing the vigour, improving morphological and yield attributing traits. The Niger seeds were exposed to four different colchicine concentrations (0.025,0.05,0.1 and 0.2%) at different time duration (6, 16, 24 and 48 hrs.). The experiment was carried out in two different conditions i.e., ex-vitro and in-vitro. The survival percentage of treated plants was found better under in-vitro conditions while the mortality rate was found higher in ex-vitro condition. The germination percentage was found higher in control as compared to colchicine treated except the 16 hrs treatment at 0.05% and 0.1% which showed similar germination as control. On assessing the morphological parameters including plant height, number of branches per plant, capitulum size, number of capitulum per plant and seed yield per plant, the treated plantlets with 0.05% and 0.1% colchicine at 16 hrs.showed increment compared to control. Stomatal length and width were found increased whereas stomatal density per microscopic area was found higher in control plants. The size of the cell and nucleus was also found increased in the above treatment as compared to control. Comparing the morphological and cytological results it can be anticipated that the plants treated for 16 hrs at 0.05% and 0.1% colchicine concentration may show the putative polyploidy.

Nitrogen Addition Affects Interannual Variation in Seed Production in a Tibetan Perennial Herb.

The variability observed in the annual seed production of perennial plants can be seen as an indication of changes in the allocation of resources between growth and reproduction, which can be attributed to fluctuations in the environment. However, a significant knowledge gap exists concerning the impacts of nitrogen addition on the interannual seed production patterns of perennial plants. We hypothesized that the addition of nitrogen would impact the annual variations in the seed production of perennial plants, ultimately affecting their overall reproductive efficiency. A multiyear field experiment was conducted to investigate the effects of varying nitrogen supply levels (e.g., 0, 4, and 8 kg N ha-1 yr-1 of N0, N4, and N8) on vegetative and floral traits, pollinator visitation rates, and seed traits over a period of four consecutive years. The results showed that the N0 treatment exhibited the highest levels of seed production and reproductive efficiency within the initial two years. In contrast, the N4 treatment displayed its highest level of performance in these metrics in the second and third years, whereas the N8 treatment showcased its most favorable outcomes in the third and fourth years. Similar patterns were found in the number of flowers per capitulum and the number of capitula per plant. There exists a positive correlation between aboveground biomass and several factors, including the number of flowers per capitulum, the number of capitula per plant, the volume of nectar per capitulum, and the seed production per plant. A positive correlation was found between pollinator visitation and the number of flowers per capitulum or the number of capitula per plant. This implies that the addition of N affected the maintenance of plant aboveground biomass, flower trait stability, pollinator visitation, and, subsequently, the frequency of seed production and reproductive efficiency. Our results suggest that augmenting the nitrogen content in the soil may have the capacity to modify the inherent variability in seed production that is observed across various years and enhance the effectiveness of reproductive processes. These findings have the potential to enhance our comprehension of the impact of nitrogen addition on the reproductive performance of perennial herbaceous plants and the underlying mechanisms of biodiversity in the context of global environmental changes.

Summer grazing change fitness in a Tibetan lotus

It is believed that grazing has an effect on the functioning and performance of flowers, as well as their association with pollinator preferences and plant reproduction. However, the effects of grazing time on nectar secretion and pollen removal are still not fully understood. We hypothesized that seasonal grazing influences pollinator visitation and pollen removal by altering above-ground biomass and nectar secretion. In this study, we conducted field experiments to measure above-ground biomass, flower number per capitulum and capitulum number per plant, nectar volume and concentration, pollinator visitation of male- and female-phase flowers, pollen removal (e.g., number of pollens exported and deposition on a pollinator body and stigma), seed set ratio, and seed number between summer and winter grazing pastures of Saussurea stella. Our findings demonstrated that summer grazing reduced the above-ground biomass, nectar secretion, and pollinator visitation of male-phase flowers, thereby decreasing pollen export. There was a positive correlation between nectar secretion and above-ground biomass, as well as between pollinator visitation and nectar secretion, the number of pollens exported, and pollinator visitation of male-phase flowers. Experiments involving the removal of leaves revealed that a decrease in above-ground biomass was associated with a decrease in nectar secretion, pollinator visitation of male-phase flowers, and pollen removal. However, plants growing in summer and winter grazing pastures had comparable nectar secretion, pollinator visitation of female-phase flowers, seed number, and seed set ratio. Our results suggested that seasonal grazing influences nectar rewards, pollinator preferences, pollen removal, and male fitness. These findings would shed new light on the influence of herbivores on plant-pollinator interactions in the Tibetan meadow.

Mutagenic effect of gamma rays and EMS on agronomical traits of niger (Guizotia abyssinica Cass.)

This study was conducted to augment genetic variability in niger plant (Guizotia abyssinica Cass.) using gamma rays and ethyl methane sulphonate (EMS) Niger (G. abyssinica) seeds of cultivar N-71 were exposed to various doses of gamma rays which ranged from 24 to 28 KR and different concentrations of EMS which ranged from 0.2 to 0.4% and in combination. Morphogenic and agronomic traits in the M1 and M2 generations that analyzed included: percentage of germination and survival, plant height, number of branches, capitulum size, number of ray florets per capitulum, number of disc florets per capitulum, head size, number of capitula per plant, number of seeds per capitulum, seed yield per plant and 1000-seed weight. The results of the present study showed that the three gamma irradiation doses used (24, 26 and 28 KR) had decreasing effect in most of the agronomic and morphological traits evaluated in M1. However, combination treatments like 24 KR+0.2% EMS and 26KR+0.4% EMS showed a noteworthy increase of grain yield and yield related components. In general, for the three irradiation doses in M1 population, there were no significant changes observed in morphological traits, however, in progenies of collective mutagenic treated seeds some potential high-yielding mutants were identified.

Sodium Nitroprusside Improves the Growth and Behavior of the Stomata of Silybum marianum L. Subjected to Different Degrees of Drought.

The use of growth-stimulating signals to increase the tolerance of plants to water deficits can be an important strategy in the production of plants in dry areas. Therefore, a split-plot experiment with three replications was conducted to evaluate the effects of sodium nitroprusside (SNP) application rate as an NO donor (0, 100, and 200 µM) on the growth and yield parameters of Silybum marianum L. (S. marianum) under different irrigation cut-off times (control, irrigation cut-off from stem elongation, and anthesis). The results of this study showed that with increasing drought severity, leaf RWC, proline content and capitula per plant, 1000 grain weight, plant height, branch per plant, capitula diameter, and the biological and grain yield of S. marianum decreased significantly, whereas the number of grains per capitula increased compared with the control. Also, by irrigation cut-off from the stem elongation stage, the density of leaf stomata at the bottom and top epidermis increased by 64% and 39%, respectively, and the length of the stomata at the bottom epidermis of the leaf decreased up to 28%. In contrast, the results of this experiment showed that the exogenous application of nitric oxide reduced the negative effects of irrigation cut-off, such that the application of 100 µM SNP enhanced RWC content (up to 9%), proline concentration (up to 40%), and grain (up to 34%) and biological (up to 44%) yields in plants under drought stress compared with non-application of SNP. The decrease in the number of capitula per plant and capitula diameter was also compensated by foliar application of 100 µM SNP under stress conditions. In addition, exogenous NO changed the behavior of the stomata during the period of dehydration, such that plants treated with SNP showed a decrease in the stomatal density of the leaf and an increase in the length of the stomata at the leaf bottom epidermis. These results indicate that SNP treatment, especially at 100 µM, was helpful in alleviating the deleterious effects of water deficiency and enhancing the tolerance of S. marianum to withholding irrigation times.

Physiological Changes and Yield Components of Safflower (Carthamus tinctorius L.) Lines as a Function of Water Deficit and Recovery in the Flowering Phase

Since climate changes have caused water restrictions, safflower stands out as an alternative crop due to its adaptability to restrictive soil and climate conditions. Thus, this research aimed to evaluate the physiological and yield performance of four safflower lines (IMA 02, IMA 04, IMA 14, and IMA 21) under two water regimes [without water deficiency—around 22% soil moisture content—100% of field capacity (FC); and with water deficiency—50% of FC]. The water regimes were imposed for 30 days during the flowering phase, followed by rehydration for 20 days. Water deficiency decreased relative water content, water potential, photosynthetic pigment contents, photosynthetic performance, maximum variable and potential quantum yield of PSII, electron transport rate, and photochemical quenching. In contrast, it increased electrolyte leakage, water use efficiency, and non-photochemical quenching. The decreases in photochemical efficiency and photosynthetic performance as a function of water deficiency caused reductions in the number of capitula, 100-grain mass, and harvest index, with more significant reductions in IMA 02, which was considered susceptible to soil water changes. IMA 04, IMA 14, and IMA 21 were considered tolerant because their physiological variables and yield components were less affected by water restriction, and they also showed recovery after rehydration compared to IMA 02. Thus, these lines can be recommended for commercial use, and safflower breeding programs aiming to select superior genotypes under drought conditions.

Foliar Applications of ZnO and Its Nanoparticles Increase Safflower (Carthamus tinctorius L.) Growth and Yield under Water Stress

Foliar application or minerals is a methodology to promote growth and/or yield and to protect plants against different kinds of stresses. Currently there is a great interest in evaluating the effect of nanoparticles for enhancing the effect of these treatments. This study was performed to evaluate and compare the effect of foliar application of zinc oxide (ZnO) and zinc oxide nanoparticles (ZnO-NPs) on the growth and yield of safflower under different irrigation regimes. Foliar applications of ZnO in all concentrations (4, 6, 8, 10, 12, and 14 g L−1) led to an increase in biomass yield, number of capitula per plant, number of seeds per capitulum, and grain yield of plants compared with control plants. The maximum increase in the studied traits was obtained with a ZnO concentration of 6, 8, and 10 g L−1. In a second round of experiments, we observed the effect of nanoparticles and found that spraying with ZnO and ZnO-NPs at a concentration of 10 g L−1 may ameliorate the deleterious effects of water deficit. The results of the present study support the idea that foliar application of ZnO improves safflower yield, especially under drought stress, and showed that using of nanoparticles increases the efficiency of the application.

大九湖沼泽湿地大泥炭藓种群分布特征及其制约因素

PDF HTML阅读 XML下载 导出引用 引用提醒 大九湖沼泽湿地大泥炭藓种群分布特征及其制约因素 DOI: 10.5846/stxb202102250528 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(42101065); 湖北省中央引导地方科技发展专项(2019ZYYD050); 神农架金丝猴保育生物学湖北省重点实验室开放基金项目(SNJGKL202101) Distribution characteristics of Sphagnum palustre L. population and its influencing factors in Sphagnum wetland of Dajiu Lake Author: Affiliation: Fund Project: The National Natural Science Foundation of China (42101065)；The Central Government Guides Local Science and Technology Development Projects of Hubei Province, China (2019ZYYD050)；The Open Fund of Hubei Key Laboratory of Shennongjia Golden Monkey Conservation Biology(SNJGKL202101) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探究神农架大九湖泥炭藓湿地的关键物种大泥炭藓(Sphagnum palustre L.)种群的分布特征及其制约因素,于2020年8月沿垂直湖岸带方向设置样带和样方进行植被和环境因子的调查和采样,于室内进行各理化指标和生理指标的测定与分析。研究结果显示:(1)大泥炭藓三生长指标(头状枝数量、盖度、生物量)对垂直湖岸带距离的响应具有一致性,均随垂直湖岸带距离的增加呈现先增加后减小的趋势,在距湖岸40m左右时,大泥炭藓种群生产力最高;(2)多元线性回归分析结果显示,在20个环境因子(土壤含水量、容重、孔隙度、固相比、液相比、气相比、pH、TN、TP、TOC、AHN、AP、TOC/TN、TOC/TP、TN/TP;地下水埋深;水样pH、TN、TP、TN/TP)中,地下水埋深是影响大泥炭藓种群生长和分布的最重要环境因子,其次是土壤TOC/TP;在8个生理指标(组织TC、TN、TP、TC/TN、TC/TP、TN/TP、总叶绿素、类胡萝卜素)中,组织TC与大泥炭藓生长显著相关;(3)地下水埋深通过影响大泥炭藓头状枝的光合和呼吸作用,土壤TOC通过影响大泥炭藓吸收同化到自身组织中的TC含量,来影响其种群的生长和分布;(4)除了非生物因子,维管植物的种间作用等生物因子也影响着大泥炭藓种群的生长和分布。本研究可为亚热带山地泥炭藓湿地的保护和恢复提供理论依据和科学指导。 Abstract:Sphagnum species, as the peatland ecosystem engineer, play a key role in both succession of plant communities and development of ecological functions in Sphagnum wetlands. In order to explore the distribution characteristics and its influencing factors of the key species -Sphagnum palustre L. population in Sphagnum wetland of Dajiu Lake, Shennongjia, we carried out the field investigation and sampling for both vegetation and environmental factors in August 2020, by setting belt transects and quadrats along the outward direction perpendicular to lakeshore. A total of 33 quadrats including 11 types of plant communities were investigated and the corresponding soil and pore water samples were collected, then a series of physical and chemical indicators and physiological indicators were determined and analyzed in the laboratory. Combined curvilinear regression analysis, multiple linear regression analysis with Pearson correlation analysis, our results showed that: (1) with the increasing vertical distance away from lakeshore, each of the three growth indicators (number of capitula, coverage, and biomass) of S. palustre showed the increased trend at first and then decreased, with the largest productivity of S. palustre population occurred at about 40 m away from the lakeshore vertically. (2) The multiple linear regression analysis showed that among the twenty environmental factors, water table depth was the most important one affecting growth and distribution characteristics of S. palustre population, followed by the soil ratio of total organic carbon content to total phosphorus content (TOC/TP). Among the eight physiological indicators [the tissue total carbon content (TC), the tissue total nitrogen content (TN), the tissue total phosphorus content (TP), the tissue ratio of total carbon content to total nitrogen content (TC/TN), the tissue ratio of total carbon content to total phosphorus content (TC/TP), the tissue ratio of total nitrogen content to total phosphorus content (TN/TP), total chlorophyll content, and carotenoids content], only tissue TC significantly affected S. palustre growth and thus its population distribution characteristics. (3) Water table depth affected photosynthesis and respiration of S. palustre capitula, and soil total organic carbon content (TOC) affected C absorption and C assimilation in S. palustre tissue, which further affected its population growth and distribution characteristics. (4) In addition to abiotic factors, the biotic factors such as the interspecific interaction of vascular plants also played the important roles in the growth and distribution characteristics of S. palustre population. Compared with Veratrum nigrum, which had dense lamina at its basal section of stem and thus larger shading coefficient, the sedge plant Eriophorum comosum, at coverage of 60%, was more favorable for S. palustre. This study provides scientific guidance for Sphagnum wetlands protection and restoration in the subtropical mountain regions. 参考文献 相似文献 引证文献

Genetic Variability Studies for Yield and Its Attributing Traits in Niger (Guizotia abyssinica (L.f.) Cass)

The experiment was conducted during Kharif 2020 and 2021 at Jawaharlal Nehru Krishi Vishwavidyalaya, Jabalpur, Madhya Pradesh, India. A total of 103 accessions including 03 checks were assessed and observations were recorded for ten traits viz., days to flower initiation, days to 50 % flowering, days to maturity, plant height (cm), number of primary branches per plant, number of secondary branches per plant, number of capitula per plant, number of seeds per capitula, 1000 seed weight (g) and seed yield per plant (g). REML analysis discovered significant differences among the 103 accessions for all the traits. It indicates a satisfactory amount of genetic variability among the accessions for yield and yield-attributing traits. Values of phenotypic coefficients of variation were higher than the value of genotypic coefficients of variation in this study. High heritability was noted for all the traits under the experiment. Genetic advance as a percentage of mean recorded high for seed yield per plant followed by number of capitula per plant, number of seeds per capitula, number of primary branches per plant, number of secondary branches per plant, 1000-seed weight whereas, trait days to 50% flowering, days to flower initiation and days to maturity exhibited low magnitude. These results indicate the dominance of the additive gene effect, which will aid in selection in an early segregating generation.

Chitosan and Titanium Dioxide Are More Effective in Improving Seed Yield and Quality in Nanoparticle Compared to Non-Structured Form: A Case Study in Five Milk Thistle Ecotypes (Silybum marianum (L.) Gaertn.)

Milk thistle is an important medicinal crop. In this two-year field study, the optimal form [bulk (non-structured), nanoparticles (NPs)] and concentration (0, 50, 100 mg L−1) of chitosan and titanium dioxide (TiO2) applications for improving seed yield, as well as seed mineral (N, Mg, Fe, Ti), protein, and oil contents were investigated in five ecotypes. Leaf gas exchange, ratio of variable to maximum fluorescence (Fv/Fm), and hydration were also evaluated in situ. Chitosan and TiO2 improved all traits under study, with the former generally being more effective. When applied in the NP form, the positive effect was stronger. For chitosan NPs, a low concentration was optimal. Increased hydration status was associated with enhanced stomatal conductance, which, together with Fv/Fm, were positively related to photosynthetic rate. The seed yield per plant was positively related to main capitulum traits (i.e., diameter, number, and weight of seeds), as well as to seed weight and number of capitula per plant. In conclusion, the improvement of seed yield and quality by application of chitosan and TiO2 in either form was underlain by the same components, though their relative importance depends on the ecotype. Chitosan NPs were most effective, demonstrating an economical, eco-friendly, and sustainable means to stimulate milk thistle yield.

Role of heterosis for photosynthetic traits and sink organs in seed yield enhancement in safflower

Abstract Genetic basis of heterosis has been exploited for yield improvement in safflower (Carthamus tinctorius L.) but little is known about physiological basis of heterosis for yield. The objective of this study was to quantify the physiological basis of heterosis for seed yield in safflower by examining 19 safflower hybrids and their parents for photosynthetic traits, and yield and its components. The results showed that heterosis for yield and its components was high and positive but was low and negative for photosynthetic traits in most of the hybrids studied. There were weak and non-significant relations between photosynthetic traits and yield and its components. Hybrids were more efficient in translocating photoassimilates to two major sink organs viz., number of seeds and number of capitula despite having low net photosynthesis than parents. Seed yield increase in safflower is more sink-than source-limited and was necessary through heterosis for sink organs. Heterosis breeding for larger sink size with parallel increase in effectiveness of sink organs in translocation of photo-assimilates is suggested for yield improvement in safflower.

Salicylic Acid Foliar Spray Enhanced Silybum marianum Growth and Yield, as Well as Its Chemical Constituents and Chalcone Synthase Gene Activity

Silymarin, a secondary metabolite found mainly in the Silybum marianum L. fruits, has been associated with the hepatoprotective activity of the plant. Among various elicitors, salicylic acid, a “Generally Regarded As Safe” compound recognized by the Food and Drug Administration, is one of those being used in the induction and enhancement of valuable plant secondary metabolite production in various plant species. In this study, two concentrations (10−4 and 10−3 molar) of salicylic acid have been applied to the S. marianum plants as foliar spray to investigate their effects on plant growth and yield, as well as the production of its bioactive compound, silymarin. Our results indicated that both concentrations of salicylic acid increased the plant height, the number of branches, leaves, and capitula, as well as the dried weight of roots, aerial parts, and fruits. The enhancement effects in plant growth and yield were accompanied by an increase in photosynthetic pigments such as chlorophyll-a, b, and carotenoids as well as element contents such as nitrogen, phosphorus, and potassium. The potential of salicylic acid as an elicitor for the enhancement of secondary metabolites in S. marianum was supported by the increase in silymarin’s major components, silybin (A + B), in the salicylic acid-treated plants. Concomitant expressions of CHS1, 2, and 3 genes that have been associated with the production of silymarin in S. marianum were also observed in the salicylic acid-treated plants. A lower concentration (10−4 M) of salicylic acid was found to be a better elicitor as compared with the 10−3 M salicylic acid. An increase of 3.4 times in capitula number and fruit dried weight as well as 2.6 times in silybin (A + B) contents were observed in plants sprayed with 10−4 M of salicylic acid as compared with the control.

Determination of optimum plant characters in safflower (Carthamus tinctorious L) under rice based late sown condition

The current experiment consisting of 19 elite safflower genotypes along with three checks (A-1, PBNS-12 and DSH 185) were sown in randomized block design in three replications. Genotypic correlation studies established a positive association between the number of capitulum per plant, the number of seeds per plant, the weight of 100 seeds per plant and the seed yield per plant. As a result, selecting genotypes based on these traits may help to enhance&nbsp;seed yield. Days to maturity and the number of seeds per capitulum had a positive&nbsp;association with oil content, indicating that delayed maturity contributed to enhance&nbsp;oil content. Similarly, the number of seeds/capitulum contributed to improve&nbsp;the&nbsp;oil content. Days to 50% flowering, number of capitulum /plant, number of seeds /capitulum, 100 seed weight and oil percentage appeared to have the most direct effects on seed yield. Oil content per plant had a significant effect on traits such as days to 50% flowering, days to maturity, and 100 seed weight, whereas seed yield had a negative direct&nbsp;effect towards oil content. The path analysis results&nbsp;showed that increased rosette period helped plants establishing good root system at an early stage of growth, delayed days to 50% flowering and maturity strongly affecting the source and sink, which converted into the number of capitulum per plant and 100 seed weight. These characters&nbsp;showed&nbsp;a positive relationship as well as direct effects on seed yield and oil content. As a result, a plant with delayed maturity (130-135 days), medium plant height (110cm), 30-35 seeds per capitulum, 100 seed weight (4.5-5 g) and oil content (32-33 %) would be considered as the model plant type for late sown irrigated conditions in Chhattisgarh plain. Keywords: Model plant type, source, sink, correlation, path analysis

Hybrid vigour and inbreeding depression analysis for seed yield and its related attributes in safflower (Carthamus tinctorius L.)

The present study was conducted to decipher the genetic information on heterosis and inbreeding depression for seed yield and its contributing characters in safflower (Carthamus tinctorius L.). The cross, JMU-1339 x NARI-6, showed a positive and significant relative heterosis, standard heterosis and heterobeltiosis for seed yield per plant while, the cross, JMU-1339 x EC-757665, exhibited positive and significant relative heterosis and heterobeltiosis along with negative standard heterosis. The cross, JMU-1339 x NARI-6, noted significant desirable heterosis for other yield contributing traits viz., the number of branches, the number of capitulum and the number of seeds per capitulum and also exhibited positive significant inbreeding depression for these characters. The cross, JMU-1339 x EC-757665, showed desirable heterosis for the number of branches, the number of seeds per capitulum and test weight with positive significant inbreeding depression for these characters. Heterosis in the cross, JMU-1339 x NARI-6, was highly significant indicating its usefulness in the direct release as a variety after thorough testing over locations. The cross, JMU-1339 x EC-757665, exhibited a significant positive heterotic value for test weight and oil content revealing its usefulness in breeding programmes to enhance this trait. Key words: Heterosis and inbreeding depression, Safflower.

Ligularia pseudolamarum (Asteraceae, Senecioneae), a new species from southeastern Xizang, China

Ligularia pseudolamarum, a new species from southeastern Xizang, China, is described and illustrated. It is tentatively nested in L. sect. Ligularia ser. Ligularia based on its pinnate–palmate leaf venation, racemose synflorescence and pappus which is as long as or slightly shorter than the tubular corolla. Within the series, it is apparently closely related to both L. lamarum and L. subspicata, however, L. pseudolamarum is easily distinguished from the latter two species by its stem indumentum, leaf margin, bract texture and color, capitulum number and ray floret number and size. In addition, a distribution map and a diagnostic key to all Chinese species of L. ser. Ligularia are also provided.

Improvement of yield in Guizotia abyssinica (L.F.) Cass. by using backcross method

Guizotia abyssinica (L.F.) Cass. is one of the important oilseed crops cultivated in India. The seed of the plant is used by the tribal and rural people of our country as a source of edible oil. The present investigation of the Niger plant deals with the study of the back cross-program and improvement in the variety. Unknown local variety (A) of niger was selected as a non-recurrent parent because of having some desirable characters like less vegetative growth (dwarf), resistance to waterlogged condition, and large seed grains while IGP-76 variety (B) was selected as a recurrent parent and used as a female having characters like small black grains, resistant to leaf-eating cater Piller and powdery mildew result shows successfully transfer of the characters in the F1 generation. The average number of capitulum/plant shows very good and positive results in F1 as well as BC1 generation. As compared to the recurrent parent (B) an average number of capitulum per plant was increased in F1 generation by 14.28% and in BC1 generation by 28.5%. The table indicates that there is incensement in the average number of seeds per capitulum. The average number of seeds per capitulum was increased by 8.3% in the F1 generation and by 11.11 % in the BC1 generation as compared to the recurrent parent. Average weights of 1000 seeds were also increased in F1 generation by 31.78% and in BC1 generation by 47.28% along with the total yield per plant.

Generation Mean Analysis Studies in Safflower (Carthamus tinctures L.)

The present investigation was conducted at experimental research farm of Agriculture Botany College of Agriculture, Latur, in 2021, with a view to study the genetics of yield and yield components through generation mean analysis. The scaling test exhibited that, there was presence of epistatic gene interaction. The duplicate epistasis were observed in days to maturity and test weight in cross, JMU-1339 x NARI-6 and cross, JMU-1339 x EC-757665 for days to 50% flowering, number of branches per plant, number of seeds per capitulum and oil contents in cross-I; for plant height, number of capitulum per plant and hull contents in cross, JMU-1339 x EC-757665. This suggests the need of specific breeding procedure such as intermating of most desirable segregants followed by selfing and selecting superior genotypes coupled with progeny testing to exploit the population under study. Selection in early generation would be effective when additive effects are larger than non-additive ones. Further if the non-additive portions are larger than additive one, the improvement of the character need intensive selection through later generations.