Breeding technique of Selenothrips rubrocinctus (Giard, 1901) (Thysanoptera: Thripidae) on roses leaflets

The development of adequate methods for maintaining populations of arthropod organisms in the laboratory has been a challenge due to the characteristics of each species. This work has aimed to define a method for breeding Selenothrips rubrocinctus (Giard, 1901) in rose leaflets in order to study this species in the laboratory. A condition which could maintain the leaflets turgor for a longer time was sought, in order to guarantee both the survival and multiplication of the insects, and less influence of abiotic factors. Four types of substrates were tested: a) a filter paper disk moistened with distilled water covering the bottom of a Petri dish and; b) a vegetable sponge moistened with distilled water surrounding the base of the leaflet; c) a potato, dextrose and agar (BDA) in a microcentrifuge tube surrounding the base of the leaflet; and d) hydrogel in a microcentrifuge tube surrounding the base of the leaflet. The filter paper moistened with distilled water allowed 65% of the leaflets to remain turgid over a 10-day period and was the most suitable substrate for thrips breeding. With the results at hand, we described S. rubrocinctus breeding in the laboratory. The adopted methodology provided the population density stability of the bred insects, as well as the obtainment of specimens of S. rubrocinctus in quantity and quality throughout the entire period of development of studies on the biology of the species.

Shuttle breeding in sunflower lines development

Shuttle breeding is a breeding system where generations undergo sequential evaluations at different locations, developed by N. Borlaug. Our study aims to demonstrate an opportunity of application shuttle breeding method in sunflower lines development and also to show its advantages and disadvantages. Experiments were mainly conducted at the Central Station (Krasnodar) of All-Russia Research Institute of Oil Crops (VNIIMK). Krasnodar region is situated in the Southern part of Russia near the Black Sea. Part of our work was made at Seed and Plant Improvement Institute (Karaj, Iran) and Experimental Station near Borozdjan (Busher Province of Iran). Released and experimental sunflower hybrids and lines of VNIIMK breeding were used as a material. The experimental design was randomized blocks with three replications. Each replication had four rows and two central rows were analyzed only to exclude the border effect. It is shown that the application of the shuttle breeding technique to sunflower was highly successful and results in elite line development.

Development of non-transgenic glyphosate tolerant wheat by TILLING

Glyphosate (N-phosphonomethyl-glycine) is the world’s most widely used broad spectrum, post-emergence herbicide. It inhibits the chloroplast-targeted enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS; EC 2.5.1.19), a component of the plant and microorganism-specific shikimate pathway and a key catalyst in the production of aromatic amino acids. Variants of EPSPS that are not inhibited by glyphosate due to particular amino acid alterations in the active site of the enzyme are known. Some of these variants have been identified in weed species that have developed resistance to glyphosate because of the strong selective pressure of continuous, heavy glyphosate use. We have used TILLING (Targeting Induced Local Lesions in Genomes), a non-transgenic, target-selected, reverse genetics, mutation breeding technique, and conventional genetic crosses, to identify and combine, through two rounds of mutagenesis, wheat lines having both T102I and P106S (so-called TIPS enzyme) mutations in both the A and the D sub-genome homoeologous copies of the wheat EPSPS gene. The combined effects of the T102I and P106S mutations are known from previous work in multiple species to minimize the binding of the herbicide while maintaining the affinity of the catalytic site for its native substrates. These novel wheat lines exhibit substantial tolerance to commercially relevant levels of glyphosate.

CRISPR-Cas9 Gene Editing for Fruit and Vegetable Crops: Strategies and Prospects

Fruit and vegetable crops are rich in dietary fibre, vitamins and minerals, which are vital to human health. However, many biotic stressors (such as pests and diseases) and abiotic stressors threaten crop growth, quality, and yield. Traditional breeding strategies for improving crop traits include a series of backcrosses and selection to introduce beneficial traits into fine germplasm, this process is slow and resource-intensive. The new breeding technique known as clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 (Cas9) has the potential to improve many traits rapidly and accurately, such as yield, quality, disease resistance, abiotic stress tolerance, and nutritional aspects in crops. Because of its simple operation and high mutation efficiency, this system has been applied to obtain new germplasm resources via gene-directed mutation. With the availability of whole-genome sequencing data, and information about gene function for important traits, CRISPR-Cas9 editing to precisely mutate key genes can rapidly generate new germplasm resources for the improvement of important agronomic traits. In this review, we explore this technology and its application in fruit and vegetable crops. We address the challenges, existing variants and the associated regulatory framework, and consider future applications.

Physiological changes in advanced hybrid chestnuts do not alter blight resistance under co-occurring drought

Chestnut breeding programs have been using a backcross breeding technique to produce trees with a predominantly American chestnut (<i>Castanea dentata</i>) genome and chestnut blight disease resistance from Chinese chestnut (<i>Castanea mollissima</i>). The potential for other physiological changes caused by breeding has yet to be widely studied. We quantify chestnut (American, Chinese, and BC₃F₃ hybrids) responses to water-stress and measure how co-occurring drought influences disease severity. The experiment was completed using 172 bare-root seedlings organized into a completely randomized factorial design in an outdoor rain-out shelter for one growing season. BC₃F₃ hybrid gas exchange (A_sat, g_s) rates were more similar to Chinese than American chestnuts over a 20-day dry-down period, and hybrid turgor loss point showed a more intermediate (between Chinese and American) response. The relationship of stomatal conductance to mid-day leaf water potential (Ψ_md) also exhibited both American and Chinese characteristics in the hybrid trees. There was no effect of drought on the disease severity for any of the chestnut groups. We find evidence that drought physiology has been altered in some BC₃F₃ hybrids, but do not find changes in disease severity when chestnuts are under co-occurring drought.

Nutrient Content for Newly Improved Breeding Rice Lines from Parentage of the Kavuni and CO 50

The objective of the study was determining the physical properties and minerals composition in the twenty three breeding lines and two parent rice varieties. Physical properties found that no significant difference in terms of shape and size of the grain. The calcium, iron and zinc content of rice samples in the ranged from 7.56 to12.72 mg/100g, 0.73 to 2 mg/100g and 2.29 to 3.39 mg/100g, respectively. Results showed that the cultures 144-5 (12.72 mg/100g)>155-3(12.62 mg/100g)>144-2(12.61 mg/100g) =148-2 (12.61 mg/100g) contained higher levels of calcium content. Among the rice lines accessions, the samples: 144-2 (2.04 mg/100g)>32-2 (2 mg/100g)>145-2 (1.67 mg/100g)>145-3 (1.57mg/100g) had higher contents of iron. The zinc content of rice lines ranked in the following decreasing order; 144, 144-1,144-2, 144-3, 145-3, 145-6, 143-1,148-2,271-2. From the twenty three rice lines, some of the rice lines contained more minerals than of parent kavuni. The finding indicated that the cross breeding technique may increases not only the yield and also nutrient content of rice.

Development of PCR-Based Marker for Resistance to Fusarium wilt Race 2 in Lettuce (Lactuca Sativa L.)

Resistance to multiple races of Fusarium wilt is considered a critical trait for lettuce (Lactuca sativa L.) cultivars, as it is directly related to grower profitability in Japan. We analyzed F2 individuals obtained from a cross between ‘VI185’ (resistance to race 2) and ‘ShinanoGreen’ (susceptible to race 2), and applied a bioassay to the F3 population using the race 2 pathogen. ddRAD-seq analysis showed that a single semi-dominant locus on LG1 (qFOL1.2) controls resistance, and that the genotype of a RAD-marker designated as LG1_v8_117.181Mbp showed complete co-segregation with the resistance phenotype based on the F2 population. Fine mapping by PCR-based markers further revealed that qFOL1.2 were located in the position of 116.468-117.974Mbp. The 42 cultivars were evaluated for the genotypes and phenotypes using the PCR-based makers designed at this region. As a result of genotyping, all of the susceptible cultivars had the same genotype in this region, but the resistant cultivars had the diversity in the genotype. Notably, the genotype of the PCR-based marker designated as LG1_v8_116.506Mbp was consistent across the 25 resistant cultivars. Thus, we reasoned that LG1_v8_116.506Mbp was a broadly useful marker for selection of race 2-resistance. Our results provide additional breeding technique for resistance to race 2, and can accelerate pyramiding of resistance loci to multiple races of fusarium wilt.

Development of Induced Breeding Technique for Freshwater Fish Gobi, Glossogobius giuris (Hamilton, 1822) Using Pituitary Gland (PG) Extract

This study aimed to establish induced breeding technique of freshwater fish gobi (Glossogobius giuris), using the pituitary gland (PG) extract. Six experiments were conducted at the Department of Fisheries Biology and Genetics, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh, Bangladesh. First breeding trial was conducted in June using 40, 45, and 50 mg PG kg-1 body weight of the female fish. None of the fish was ovulated in the 1st trial. Two more breeding trials were conducted in July and August, using 6 mg (T1), 8 mg (T2) and 10 mg (T3) PG kg-1 body weight of female, and 3 mg (T4), 4 mg (T5) and 5 mg (T6) PG kg-1 body weight of male fish. After treatment, the ovulation rates were recorded as 56.33±1.53, 82.67±2.52 and 75.33±1.53% in July and 58.00±2.65, 94.67±1.53 and 78.33±1.53% in August under the treatments T1, T2 and T3, respectively. Hatching rates of eggs were observed as 52.00±4.36, 81.67±3.21 and 72.33±6.03% in July, and 54.67±3.23, 91.67±3.06 and 73.67±5.13% in August under the T1, T2 and T3, respectively. Hatching time was ranged from 35 to 48 h and after the absorption of yolk sac (60-72 h), they were survived well when fed with tubificid worms and mixed zooplankton. The female treated with the dose of 8 mg PG kg-1 body weight in August showed the best performance so far as the ovulation, fertilization and hatching rates were concerned, while the single dose of 4 mg kg-1 body weight of PG was found to be effective for male fish in both months. The findings obtained from the present study reveals that induced breeding of G. giuris, using PG extract is successful for large scale production of quality seed in captive condition, which would further facilitate towards the aquaculture production and biodiversity conservation of this important fish species to a greater extent.

Review of Horseradish Breeding for Improved Root Quality and Yield in Illinois, USA

Horseradish cultivars are highly heterozygous clones and are maintained through asexual propagation, using root cuttings. For many years, horseradish was believed to be sterile and therefore impossible to improve by traditional sexual crosses. Prior to the 20th century, the only way to improve horseradish was to select and plant root cuttings from the most desirable plants. Moreover, the development of new improved horseradish cultivars has also been somewhat limited by the lack of viable seed resulting from low fertility of horseradish flowers. However, in Illinois, USA, a horseradish breeding program was initiated in the 1950s to develop additional cultivars to widen the genetic base of the few cultivars being grown at the time. In more recent years, the proven cross breeding technique has been primarily used to obtain new genotypes of horseradish, since it is more efficient in producing new improved cultivars, compared to the polycross method that had been previously used for decades to obtain new genetic combinations. Since horseradish is a minor specialty crop with very little available information regarding breeding procedures, this review was developed to provide a better understanding of pollination barriers and methods for fertility improvement, traditional breeding procedures and cultivar development, and traditional breeding achievements and limitations. The development of new horseradish cultivars is essential for the sustained success of the Illinois, USA industry since it provides growers with a continuous supply of new selections that have increased vigor, outstanding root quality, and high yields.

Induction Of Ovulation Using Ovaprim And Its Impact On Reproductive Parameter Of Clarias gariepinus

Sustainability of the aquaculture industry can be secure through the induce breeding technique. One way that induce breeding can do is to increase the rate of maturation and ovulation in making sure the availability of good quality fish seed all year round. Here, we investigate how Ovaprim hormone impact the reproduction of Clarias gariepinusincluding spawning rate, fecundity, hatching and survival rate. For this purpose, Six broodstocks were divided in three experimental treatments and injected intramuscularly with different doses of Ovaprim hormone of T1: 0.25ml/kg for female and 0.125ml/kg for male, T2: 0.5ml/kg for female and 0.25ml/kg for male and T3: 1.0ml/kg for female and 0.5ml/kg for male. According to our results, broodstock injected with Ovaprim hormone of dose of T3: 1.0ml/kg for female and 0.5ml/kg for male showed higher eggs production and hatching rate compared to other treatment. The results of this study suggest that a dosage of 1.0ml/kg Ovaprim for female and 0.5ml/kg for male have a better effect on the reproductive parameter of Clarias gariepinus.