The different responses of rice genotypes to heat stress associated with morphological, chlorophyll and yield characteristics

Sixteen rice genotypes were planted under normal and high temperature during 2018 and 2019 seasons to understand the mechanisms that make plants tolerant or susceptible to heat stress and methods which may lead to generate new varieties with sustainable yield production. The combined analysis showed significant differences at the level of probability 0.05 and 0.01 among years for all characters except, chlorophyll content and leaf rolling which would indicate wide differences among the weather of both years. Environment’s variance was significant at the level of probability 0.01 over all characteristics. The significant differences at the level of probability 0.01 were recorded among genotypes and G x E interaction variances for all characteristics. The highest values of panicles number plant-1 were obtained from ‘Giza 178’ and ‘Hybrid 2’, however, the highest values of 100-grain weight were recorded with ‘Giza 179’ and ‘Egyptian Yasmine’. The minimum values of sterility% were recorded with ‘Sakha 107’ and ‘IET1444’. Concerning the cultivars performance across two environments, the cultivars ‘Giza 178’, ‘Giza 179’, ‘Sakha 107’ and ‘IET 1444’ gave the best desirable values over natural and heat stress so, those cultivars are considered to play a vital role in breeding program to enhance heat stresses tolerance accompanied with high yield potential.

Diploid mint (M. longifolia) can produce spearmint type oil with a high yield potential

Mint oil is a key source of natural flavors with wide industrial applications. Two unbalanced polyploid cultivars named Native (Mentha Spicata L) and Scotch (M. × gracilis Sole) are the main producers of spearmint type oil, which is characterized by high levels of the monoterpenes (−)-carvone and (−)-limonene. These cultivars have been the backbone of spearmint oil production for decades, while breeding and improvement remained largely unexplored, in part, due to sterility in cultivated lines. Here we show that sexual breeding at the diploid level can be leveraged to develop new varieties that produce spearmint type oil, along with the improvement of other important traits. Using field trials and GC-FID oil analysis we characterized plant materials from a public germplasm repository and identified a diploid accession that exhibited 89.5% increase in oil yield, compared to the industry standard, and another that produces spearmint type oil. Spearmint-type oil was present at high frequency in a segregating F2 population (32/160) produced from these two accessions. Field-testing of ten of these F2 lines showed segregation for oil yield and confirmed the production of spearmint-type oil profiles. Two of these lines combined high yield and spearmint-type oil with acceptable analytic and sensory profiles. These results demonstrate that spearmint-type oil can be produced in a diploid background with high yield potential, providing a simpler genetic system for the development of improved spearmint varieties.

Assessment of Genetic Diversity for Yield and its Attributing Traits in Tomato (Solanum lycopersicum L.) Genotypes for Protected Conditions

Background: Tomato plant has high yield potential, although the yield is very low because of non-availability of superior cultivars for protected cultivation. Presence of diversity is an important for variety development. Hybridization among divergent parents is probably produce ample variability and helps to isolate superior recombinants. So, the study was carried out to assess of genetic diversity in tomato for choosing promising and genetically diverse parents for improvement in yield for protected cultivation. Methods: Fourteen genotypes of tomato were planted inside naturally ventilated polyhouse during September 2018 to May 2019. The data were recorded for twenty-one characters from randomly five tagged plants from each genotype and genetic diversity was computed by utilizing Mahalanobis D2 analysis. Result: All genotypes were arranged into five highly divergent clusters in which cluster I contain maximum genotypes followed by cluster II. The intra cluster distance was highest in cluster I and inter-cluster distance was highest among cluster-II and V. Cluster means indicated that cluster II had high mean values for maximum traits. The highest contribution towards genetic diversity was shown by fruit yield/plant followed by number of fruits per plant. Based on breeding objectives, potential lines are selected as parents for utilization in hybridization programme.

Growth and Yield of Different Varieties of True Shallot Seed on Highland in West Sumatra, Indonesia

Cultivation of true shallot seeds has the potential to be developed in Indonesia because apart from being able to reduce the cost of providing seeds, it also has higher productivity than shallot from tubers. This study aims to determine the appearance of true shallot seed varieties that have high yield potential in the highlands of West Sumatra. The study used a randomized complete block design (RCBD) with 4 treatments of true shallot seed varieties, namely, Trisula, Bima, Lokananta, and Sanren, with 6 replications. The results showed that except for the age of harvest and the number of tubers per hill, the treatment of various varieties of true shallot seeds showed a significant effect on all observed variables. Lokananta variety has better growth component, yield component, and yields compared to other varieties (Trisula, Bima, and Sanren). Cultivation of true shallot seeds in the highlands gives lower yields than in the adapted area (lowland), except for the Trisula variety. Lokananta variety is recommended for use in the highlands of West Sumatra.

Different origin soft spring wheat varieties and lines comparative analysis

This work is devoted to the study of spring soft wheat samples collection material. Eighty collection specimens were evaluated, divided by their origin into four groups. The assessment was carried out according to the limiting characteristics for spring wheat: high productivity, stable over the years, resistance to biotic and abiotic environmental factors. A two-year field test made it possible to compare different groups in terms of yield, and to identify the most promising varieties and lines for the conditions of the Central Non-Black Earth Region. The evaluation of the collection samples of origin various groups showed that the varieties and lines of their own selection were the most adapted to the soil and climatic conditions of the Central Non-Chernozem region. The new lines of spring wheat, along with a high level of yield, showed resistance to biotic and abiotic stressors. Varieties of foreign selection are distinguished by a strong non-spreading stem, high density of the stem, as well as high resistance to the most harmful leaf diseases. Of particular interest are the varieties of the Belarusian selection Darya, Dalech, Viza, Rostan with a high yield potential at the level of 5.0-6.0 t/ha.

Observation of promising tungro resistant rice lines in West Sulawesi

Food needs, especially rice, are a priority for agricultural businesses in Indonesia. The development of the world population in general and Indonesia in particular encourages a rapid increase in rice productivity. So it is demanded to have variety of rice that is resistant to disease and has superior rice productivity. Efforts to increase rice yields can not be separated from the efforts of assembling new superior varieties that are disease resistant as well as high yield potential. One of the plant breeding activities is observation activities. To explore the potential of rice strains after the screening stage, it is necessary to evaluate the germplasm or selected rice strains so that genotype can be screened which gives a positive response to both biotic and abiotic stresses. Tungro disease is generally the main problem in efforts to increase rice productivity. Tungro disease can attack rice plants from seedlings, vegetative stadia leaves through the host of green aphrodisiacs (Nephotetix vieressens). In vulnerable rice and supportive environmental conditions, this disease can cause farmers to fail to harvest or ‘puso’. The use of resistant varieties is the most practical and economical ways of controlling tungro disease. The purpose of the study was to evaluate the resistance of the rice breeddings lines to tungro disease. The research was conducted during Planting Period II in 2019 in the endemic area of Tungro Kalukku, West Sulawesi. The genetic materials tested as many as 26 strains from the group of researcher germplasm of Tungro research station and resistant check varieties namely Inpari 36 and comparison production namely Ciherang. The results showed that the strains tested had a diversity of different resistances that showed varying responses to tungro disease. Rice breeddings the best from checker varieties Ciherang and Inpari 36 namely: Strains No.2, 10, 12, 16, and 19 can be recommended for used further testing.

Screening of tarragon accessions based on physiological and phytochemical responses under water deficit

In this study, screening of Artemisia dracunculus accessions was investigated under water deficit based on physiological and phytochemical traits. The results clearly indicated that water deficit significantly reduced the relative water content, chlorophyll, and carotenoid contents and increased malondialdehyde, electrolyte leakage, and antioxidant activities. The responses of tarragon accessions to water deficit, however, were inconsistent. The HPLC analysis revealed the presence of chlorogenic, syringic, ferulic, vanillic, chicoric, and p-coumaric acids as major phenolic acids, while quercetin and herniarin were detected as the predominant flavonoid and coumarin compounds in the extracts. Our findings revealed that the water deficit not only increased the amounts of herniarin, luteolin, apigenin, caffeic acid, and syringic acid, but also introduced quercetin that was not present under normal conditions in Estahbanat. Nevertheless, these results were highly impacted by the accession type. The results indicated that Hamadan, Varamin and Estahbanat accessions could be introduced as tolerant accessions. Given the very different responses of tarragon accessions to water deficit and the diversity between these accessions, the findings of the present study could be an effective step in identifying and achieving homogeneous, drought-tolerant and high-yield potential accessions, and may help tarragon breeding programs as well as development of cultivation.

Race diversity in dryland maize (Zea mays L.) landraces from southern Nuevo León, Mexico

Objective: To analyze the race diversity and geographic distribution of the native maize landraces currently cropped at southern Nuevo León, México. Design/Methodology/Approach: Data was obtained from 41 accessions which represent the commercial production in the dry land area, where fertilization and pest control are scarcely used. Landraces were classified according to the CONABIO guidelines for ear traits. Results: The measured accessions correspond to seven maize races and to seven interracial crosses. The two most frequent maize races were Ratón and Cónico Norteño, mostly located in the dry areas with less rain. Study Limitations/Implications: Three races, Celaya, Tablilla de Ocho and Elotes Cónicos, had not been previously reported; while two formerly reported races Tabloncillo and Olotillo, were no longer found. This study did not include the grain-colored accessions. Findings/Conclusions: Three collections stood out for producing large ears with large kernels, thus showing a high yield potential. The maize landraces harvested in dryland areas might offer advantages to be grown under harsh environments or be used as gene donors for drought tolerance.