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The utilization of germplasm of the wild species in sweet-potato breeding has been conducted for the last three decades. Such attempts brought some remarkable achievments in improving root yield, starch content and resistance to the nematodes of sweet potato. Some wild plants in polyploid series may have many genes potentially important for further improvement of the agronomic traits. However, the genomic relationship between the wild relatives and hexaploid sweet potato (2n=6x=90) has been unrevealed. Meiotic studies were carried out on the hexaploids synthesized with diploids and tetraploids and on the F_1 hybrids, when possible, with sweet potato. Chromosomes in pollen mother cells (PMC's) and root tip cells were fixed in New-comer's solution and stained according to Feulgen reaction with Schiff's reagent. The present report was concerned wlth two kinds of the synthetic hexaploids. The first was the hexaploids derived from chromosome doubling of triploid hybrids between Ipomoea lacunosa (K61, 2n=30) and I.tiliacea (K134, 2n=60). the synthetic hexaploid exhibited mostly regular meiosis with bivalents at the metaphase I stage (MI), and it was considered an allo- or segmental allo-hexaploid. The synthetic hexaploids were fertile, but failure in obtaining hybrids by crosses with sweet potato suggested a critical reproductive barrier between them. The second synthetic hexaploids with 2x I, trifida (K221, 2n=30) and 4x I,trifida (K233, 2n=60) showed the chromosome configurations characterized by the occurrence of tetravalents and hexavalents. Such multivalent associations, high in frequency and number per cell, suggested the presence of the genomes at least in quadruplicate. Similar pattern of the chromosome configura-tions was observed in a cultivar of sweet potato and the F_1 hybrid between the synthetic hexaploid and sweet potato. Consequently, the genomic formula for sweet potato was proposed as B1B1B2B2B2B2, in which B1B1 was given to 2x I.trifida and B2B2B2B2 to 4x I. trifida. However, it is necessary to clarify the degree of homology between B1 and B2 genomes for more conclusive genomic constitution of sweet potato. A brief account was given for the taxonomic identification of the wild Ipomoea strains used in the present study., サツマイモ育種では,生殖質の多様化をはかる方法の一環として,近縁野生種の育種的利用を進めてきた.その成果として,線虫低抗性をもつ高でん粉多収性の系統・品種育成をみるにいたった.サツマイモは6倍体(2n=90)で,一方,その近縁野生種には2倍体,4倍体,6倍体がある.これら野生種およびサツマイモの倍数性に関与しているゲノムについてはいまだ十分解明されていない.本報告では,野生種をもちいてできた2種類の合成6倍体,それらの両親,およびサツマイモとの交雑から生じたF_1雑種について,減数分裂第1分裂中期の染色体対合を観察し,それら植物のゲノム構成を明らかにしようとした. 第1の合成6倍体はIpomoea lacunosa(K61,2 n=30)とI.tiliacea(K134,2例=60)との3倍体雑種の染色体倍加によってえられた(Fig.1).この6倍体では,低頻度の1価, 3価,4価染色体がみられたが,平均41.3の2価染色体がみられた.そして平均43.2の2価染色体相当数があり,全体として異質または部分異質6倍体の染色体対合とみたすことができた(Table1).3倍体雑種としてはI.trichocarpa(K231,2n=30)とK134との雑種が供試された。I.lacunssaとI.trichocarpaは共通のゲノムAをもつことが明らかにたっている・またJONES(1970)によれば, I.tiliaceaは異質4倍体としての染色体対合を示している.以上のことから,I.tiliaceaのゲノム構成をA1A1TTとして,合成6倍体に暫定的たゲノム式AAA1A1TTを与えた.この合成6倍体は高い稔性をもつが,サツマイモとの交雑からは雑種を得ることはできたかった (K.A.E.S.1963).

Calos obtidos da cultura in vitro de embrião imaturo do cruzamento interespecífico L. esculentum x L. peruvianum, praticamente perderam a capacidade morfogenética, após dois anos de subcultura. Na tentativa de recuperação do processo de organogênese desses calos, realizaram-se dois experimentos, utilizando-se os fitorreguladores ácido indolacético (IAA) e 6-benziladenina (6-BA), cujas concentrações foram combinadas em dialélicos de 5 x 5 e 3 x 3. A composição de sais minerais e vitaminas baseou-se no meio de Murashige e Skoog, adicionando-se sacarose a 3% e ágar a 0,8%, e ajustando-se o pH final dos meios de cultura para 5,5. As condições para o dialélico 5 x 5 foram fotoperíodo de 16 horas de luz a 600 lux e temperatura de 25 ± 3°C. No dialélico 3 x 3, os tratamentos foram mantidos em câmara de crescimento a 2.000 lux, sob a mesma variação de temperatura e fotoperíodo. Em cada frasco, inoculou-se um calo com cerca de 1 cm³, totalizando quinze repetições. Avaliaram-se o desenvolvimento de calos, atribuindo-se uma escala de notas de 1 a 5, e a presença de plantas (organogênese) após 30 dias de cultura. Observou-se o número total de plantas por tratamento, bem como o desenvolvimento das plantas em centímetro. No dialélico 5 x 5, a organogênese foi apenas incipiente em três tratamentos, porém as melhores combinações para o desenvolvimento dos calos foram de 0,5, 2,5 e 5,0µM de IAA com 2,5µM de 6-BA. No dialélico 3 x 3, houve a indução de plantas em sete tratamentos, sendo mais eficientes 25 e 50µM de 6-BA, sem auxina. O tratamento de 0,5 e 10,0µM de IAA e 6-BA, respectivamente, permitiu simultaneamente o crescimento de calos e a regeneração de plantas. Nota-se a influência das condições ambientais de manutenção das culturas, principalmente da intensidade de luz.Callus from Lycopersicon esculentum x L. peruvianum interespecific hybrids cultured in vitro lost their morphogenetic abilities after two years. An attempt has been made to recover the organogenesis of those callus, using 5 x 5 and 3 x 3 diallelic combinations between indolacetic acid (IAA) and 6-benzyl-adenin (6-BA). Mineral salts and vitamins of the MS medium (Murashige & Skoog), were used, added with sucrose (3%) and agar (0.8%). Culture medium pH was kept at 5.5. The 5 x 5 diallelic treatments were incubated under the following conditions: day temperature = 25 ± 3°C; day length = 16 hours; light intensity = 600 lux. The 3 x 3 diallelic treatments were kept at the same conditions of daylight and temperature but at 2000 lux light intensity. Callus development and shoot formation were graded from 1 to 5, 30 days after inoculation, Shoot number and height were also evaluated. In the 5 x 5 diallelic experiment, it was observed a low number of differentiated plants. The best combinations for callus development have been 0.5, 2.5 and 5.0µM of IAA with 2.5µM of 6-BA, respectively. However in the 3 x 3 diallelic experiment, it was recorded a high frequency of shoot formation s and the most efficient treatments were the 25.0 and 50.0µM concentrations of 6-BA, without any auxin. It was also observed the influence of environmental condi-tions (mainly light intensity) on the process.

Foi constatada, citologicamente, a presença de uma translocação heterozigota envolvendo dois cromossomos não-homólogos em um híbrido entre Zea mays L. e Z. mexicana (Schrad.) Kuntze. As análises citológicas foram feitas na microsporogênese das plantas híbridas, onde se observou a característica configuração em cruz que os cromossomos translocados assumem na fase de paquíteno, bem como as configurações em cadeia ou anel na diacinese e anel torcido na metáfase I. A contagem dos grãos de pólen indicou 44,0% ± 1,2 de esterilidade, que foi atribuída diretamente à translocação e não à hibridação. Devido ao mau espalhamento dos cromossomos na fase de paquíteno, não se puderam identificar os cromossomos envolvidos na translocação, estimando-se, porém, que estejam entre os três cromossomos maiores do genoma (cromossomos 1, 2 e 3).Aheterozygous translocation involving two non homologous chromosomes was observed in a hybrid between Zea mays L. and Z. mexicana (Schrad.) Kuntze. The cytological observations were made at the microspore phase. A cross-shaped synaptic figure formed by the translocated chromosomes was shown at pachytene as well as the chain configurations at diakinesis and ring shaped formations at metaphase I. Pollen sterility was 44.0% ± 1.2 and it was probably due to the presente of lhe translocation rather than to the interspecific hybridization itself. Because of poor pachytene spreading, chromosomes involved in the translocation could not be identified. However, they appear to belong to the group of the large chromosomes (1, 2 or 3).

Nearly 450 plantlets were produced from 51 diploid Solanum etuberosum x S. pinnatisectum F1 hybrids through adventitious shoot formation on in vitro cultivated rachis and petiole explants.

The cultivation of perennial wheat might represent an economically and ecologically interesting option for extensive cultivation, particularly in marginal land. In autumn 2017, five breeding lines of perennial wheat (Triticum aestivum × Thinopyrum intermedium) and for comparison two varieties of annual wheat were sown at three sites in Bavaria. The five breeding lines were selected from a bulk originating from Washington State University. In 2018, the yield of the perennial breeding lines was 49 to 96 % of the annual cv. ‘Capo’, which reached an average of 17.4 dt/ha. In 2019, the yield was 9 to 38 % of ‘Capo’, which reached an average of 10.8 dt/ha, showing large differences between the locations. The autumn re-emergence was significantly affected by the severe drought at all sites in 2018 and 2019 and showed differences between the lines up to a total failure at one site. In the third year, the yield of the breeding lines was very low, thus a third year of cultivation cannot be recommended under these climatic and soil conditions. The yields of the plots with under-sown clover were significantly higher in the third year. A mixture with a low growing clover species is recommended because of better weed suppression. Field trials in Austria with perennial rye cv. ‘Perenne’ derived from an interspecific cross between Secale cereale and S. montanum were carried out from 2012 to 2015 in order to determine biomass yield and regrowth capability. Biomass yield of ‘Perenne’ in the early cuttings was between 70 and 95% compared to cv. ‘Elego’, but decreased to 45% after heading/anthesis for the two- and three-year crop stand. This decrease was mainly due to the reduced plant height (-45 cm) of the perennial crop in the 2nd and 3rd year compared to the first year crop. Root mass in the three-year crop was significantly higher compared to ‘Elego’ and the first and second year ‘Perenne’, but mainly only in the top 20 cm. Generally, significantly inferior grain yield was obtained for ‘Perenne’, reaching only 53%, 26% and 15% for the 1st, 2nd and 3rd year crop, respectively, compared to annual ‘Elego’ (5670 kg/ha). Similarly, a significant decrease was also observed for thousand grain weight (-32%) from the first to the third year of cultivation. Moreover, a higher number of ergot sclerotia was observed for the interspecific perennial rye hybrid compared to ‘Elego’. Weed infestation was constantly increasing in the perennial crop making a cultivation of more than 3 years not recommendable.

We have developed the first quantitative trait locus (QTL) analyses for agronomic traits in a cross between F(1.1) (P1) and F(1.7) (P7) entries of Miscanthus sinensis Anderss. Both lines are offspring of the cross between MS-90-2 and MS-88-110. A map based on random amplified polymorphic DNA markers previously constructed was used to perform the QTL analyses. This map was developed using a new mapping strategy that has been designated offspring cross. Eleven QTLs were detected for height, panicle height and diameter using the programme mapqtl 4.0 and the multiple QTL method. QTL significance was determined using several analyses, including Kruskal-Wallis analyses, empirical determination of LOD critical values using permutation tests, QTLs validation with field data over 2 years and co-localization of QTLs for correlated traits. The results obtained could be the first step in developing a marker-assisted selection programming in this species for biomass production.