Víztakarékos öntözéstechnikával termeszthető rizsfajtákra jellemző génexpressziós mintázatok = Gene expression profiles characteristic to rice varieties cultivated under water-saver irrigation regime

Eltérő vízigényű rizsfajták (''szárazrizsek'' és hagyományos fajták) növekedési, termesztési paramétereit határoztuk meg árasztásos ill csak kiegészítő öntözéses körülmények között annak érdekében, hogy a korlátozott vízellátáshoz jól adaptálódó fajtákra jellemző tulajdonságokat megállapíthassuk. Kidolgoztunk egy olyan kísérleti rendszert, melyben ezeknek a fajtáknak a gyökérnövekedését vizsgálhatjuk, illetve génexpressziós vizsgálatokhoz mintát gyűjthetünk. Transzkript profilok microarray hibridizációs felvételével megállapítottuk, hogy a mélyrehatoló, erőteljes gyökérzet meghatározó jellemzője a száraz körülmények között is jól teljesítő fajtáknak, és több száz olyan gént találtunk, melynek transzkript-szintje vízellátástól függő napszakos változásokat mutat a legnagyobb tűrőképességű Sandora fajta gyökérzetében. Valósidejű kvantitatív PCR-rel ellenőriztük számos gén expressziós mintázatát, ez döntő többségében megerősítette a microarray hibridizációval kapottakat, egyúttal más aszályérzékenységű rizsfajtákban is meghatároztuk ezen gének expressziós mintázatát. | Rice cultivars featuring different water demand (upland and traditional cultivars) were studied in this project. Growth and harvest parameters of these cultivars were determined under flooding and limited sprinkle irrigation in order to find features characteristic to genotypes adapting well to water limitation. An experimental system was established that allows studies of root growth as well as collection of samples for gene expression experiments. Microarray hybridizations revealed the transcript profile of Sandora cultivar that develops strong and deep root system which is an important component of good yield performance under drought stress. Several hundred genes were found which showed water supply dependent transcript level changes in the roots of this cultivar on a daily manner. Microarray results were confirmed by quantitative real-time PCR for several genes. The expression patterns of these genes were also checked in cultivars being less drought tolerant

Enhancement of a new method in cereal breeding programmes

Homozygous doubled haploid (DH) plants and lines can be used in cereal breeding programmes. Methods based on androgenesis induction are a common way to produce homogenous basic material for variety development and genetic research purposes. Anther culture is a simple and rapid method for DH production in case of major cereal crops like barley and wheat. Oat is known as recalcitrant species for tissue culture response specially anther and microspore culture. Its low frequency DH production limits extensive application in breeding. Our aim was to start developing an improved protocol to generate acceptable number of DH lines for breeding. Many factors (low induction rate, essential manpower needed, plant regeneration problems and genotype dependence) hinder the development and application of the methods of in vitro androgenesis. Understanding of topic “in vitro response” and “plantlet regeneration frequency” are crucial factors in cereal science, too. Our aimed results of oat (Avena sativa L.) will open new genetic solutions in plant science, plant physiology and cell- and tissue culture of cereals and in the development of new varieties

Enhancement of a new method in cereal breeding programmes

Homozygous doubled haploid (DH) plants and lines can be used in cereal breeding programmes. Methods based on androgenesis induction are a common way to produce homogenous basic material for variety development and genetic research purposes. Anther culture is a simple and rapid method for DH production in case of major cereal crops like barley and wheat. Oat is known as recalcitrant species for tissue culture response specially anther and microspore culture. Its low frequency DH production limits extensive application in breeding. Our aim was to start developing an improved protocol to generate acceptable number of DH lines for breeding. Many factors (low induction rate, essential manpower needed, plant regeneration problems and genotype dependence) hinder the development and application of the methods of in vitro androgenesis. Understanding of topic “in vitro response” and “plantlet regeneration frequency” are crucial factors in cereal science, too. Our aimed results of oat (Avena sativa L.) will open new genetic solutions in plant science, plant physiology and cell- and tissue culture of cereals and in the development of new varieties

Testing the stability of grain yield and bread-making quality of wheat varieties in two different years

25 winter-type bread wheat genotypes were evaluated in two consecutive years (2010 and 2011) in the nursery of Cereal Research Non-Profit Company (CRNPC) to test the stability of grain yield and quality traits of CRNPC-bred varieties. In spite of the earlier trends the extremely wet 2010 year’s grain yield became significantly lower and bread-making quality proved to be poorer than in the dry 2011 year. The most significant reasons of those found to be the very strong disease (mostly leaf rust and Fusarium) infection pressure in the highly precipitated 2010 year. Other, minor reasons were water logging stress, and harvest deficits due to the remarkable lodging of wheat. Stability of grain yield and different quality traits (wet gluten content, gluten stability, kernel hardness, farinograph water absorption, farinograph value, Zeleny-value, falling number) were evaluated by regression calculations to test the varieties’ adaptability to the different year effects. In case of yield, a wide variation was found in stability of grain output. In cases of quality traits, the most sensitive traits were falling number, farinograph water absorption and developing time of dough

Double-stranded RNA mycoviruses in Fusarium culmorum and Fusarium graminearum isolates

The presence of double-stranded RNA (dsRNA) elements in Fusarium culmorum and F. graminearum isolates of different origin, and the possible effect of these elements on pathogenicity and toxin production of the isolates were examined. Altogether 40 F. culmorum and 38 F. graminearum isolates were involved in this study, together with F. cerealis and F. pseudograminearum strains. Double-stranded RNA elements indicative of mycovirus infection were detected for the first time in 5 F. culmorum isolates. The isolates originated from the United States, The Netherlands, Australia and Israel. The dsRNA nature of the fragments was proved by RNase, DNase and S1 nuclease treatments. The sizes of the dsRNA elements varied between 0.6–3.95 kbp. A dsRNA element of 3.0 kbp in size was also detected in a F. graminearum isolate came from South Africa. None of the Central-European isolates examined were found to carry such elements. We also examined the mycotoxin producing abilities and pathogenicity of the dsRNA infected isolates. Four of the mycovirus infected F. culmorum isolates produced deoxynivalenol and zearalenone (chemotype I), while one of the isolates came from the USA produced nivalenol and fusarenone X (chemotype II). The dsRNA-containing F. graminearum isolate produced deoxynivalenol and zearalenone. In general, dsRNA-containing isolates were found to be as pathogenic to two wheat cultivars as dsRNA free isolates. RAPD analysis and sequence analysis of a putative reductase gene fragment indicated that dsRNA-containing isolates are scattered among dsRNA free isolates. Further work is in progress in our laboratory to characterize these dsRNA elements by sequence analysis