Relationships among alfalfa resistance to Sclerotinia crown and stem rot, Sclerotinia trifoliorum and oxalic acid

Sclerotinia crown and stem rot (SCSR) of alfalfa caused by Sclerotinia trifoliorum is one of the main constraints for efficient alfalfa cultivation in temperate climate all over the world. The resistance of 200 alfalfa accessions to Sclerotinia crown and stem rot was evaluated during 2010 to 2011 in the field nursery established in 2009. The resistance of alfalfa accessions germinating seeds to mycelium of Sclerotinia trifoliorum and oxalic acid (OA) concentrations of 10, 20, 30 mM was screened under laboratory conditions. The statistically significant differences at P<0.05 were determined among evaluated alfalfa accessions resistance to all screened factors. The reactions of alfalfa accessions to disease under field conditions showed that majority of the non-adapted accessions were heavily diseased, whereas the resistant accessions had only negligible disease severity. The germination of accessions seeds at oxalic acid concentration of 30 mM showed strong correlation (r = -0.817**, P<0.01) with SCSR severity in 2011. Among OA concentrations, this one showed the highest correlation rate with SCSR as well as was the least time consuming method. This method of seeds germination on mycelium of S. trifoliorum was unfit due to its weak correlation with SCSR and higher inputs.Keywords: Alfalfa, resistance screening, Sclerotinia trifoliorum, oxalic aci

EFFECT OF THE MORPHOLOGICAL TRAITS ON SEED YIELD OF LUCERNE BREEDING POPULATIONS IN LITHUANIA

Phenotypic correlation coefficients between seed yield and morphological traits of lucerne (Medicago sativa L.) breeding populations were determined. Ranking of populations by seed yield and subsequent calculating of correlations showed that as higher differences in seed yield among populations was as higher correlations were obtained. Among the characters examined seed yield was positively correlated with the length of raceme, number of flowers, pods and seeds per raceme, number of seeds per pod (r=0.31*, 0.61*, 0.42*, 0.57*, 0.53*, respectively). Negative relationships were determined between spring regrowth height, alfalfa mosaic, flowering period, plant regrowth height after harvest, 1000 seed weight and seed yield (r= -0.42*, -0.81**, -0.64*, -0.71*, -0.41*, respectively)

Liucernos (Medicago spp.) genetinės įvairovės tyrimai identifikuojant atsparumą patogenams ir judriajam aliuminiui

The study was designed to investigate disease resistance of lucerne (M. sativa subsp. sativa) genetic material (cultivars and breeding material) under field conditions, to evaluate Sclerotinia stem and crown rot and aluminium resistance under laboratory conditions, and to develop Sclerotinia stem and crown rot and aluminium resistant populations.Ištirti liucernos (M. sativa subsp. sativa ir M. sativa subsp. varia) genetinės medžiagos - įvairių veislių ir Lietuvos agrarinių ir miškų mokslų centro (LAMMC) Žemdirbystės instituto selekcinės medžiagos atsparumą ligoms lauko sąlygomis, įvertinti atsparumą vėžiui ir aliuminiui laboratorinėmis sąlygomis bei suformuoti atsparias aliuminiui ir vėžiui populiacijasŽemės ūkio akademijaVytauto Didžiojo universiteta

Lucerne complexive resistance to deseases

The 41 accessions of lucerne (Medicago sativa, M. varia, M. falcata) were investigated in the field experiment at the Institute of Agriculture in 2008-2009. Experiment period was very favourable for disease spread and development. Resistance between downy mildew (DM) and Sclerotinia crown and stem rot (SCSR) correlated weakly (0.344), the medium correlation (r=0.531) was determined between resistance to spring black stem and leaf spots (SBSLS) and DM, the strong correlation (r=0.704) was found between resistance to SBSLS and SCSR. The medium resistance to SBSLS was characteristic for 17 % of accessions. The resistant to DM were 14 %, and medium resistant were 29 % of accessions. About third of accessions were resistant and medium resistant to SCSR.41 liucernų (Medicago sativa, M. varia, M. falcata) pavyzdys tirtas 2008– 2009 m. lauko bandymuose Žemdirbystės institute. Bandymo laikotarpis buvo labai palankus plisti ir vystytis ligoms. Tirtų liucernos pavyzdžių atsparumas netikrajai miltligei ir vėžiui koreliavo silpnai (r=0,344), vidutinis ryšys (r=0,531) buvo nustatytas tarp atsparumo askochitozei ir netikrajai miltligei, o stiprus nustatytas (r=0,704) tarp atsparumo askochitozei ir vėžiui. Vidutiniu atsparumu askochitozei pasižymėjo 17 % pavyzdžių. Atsparių netikrajai miltligei pavyzdžių nustatyta 14 %, o vid. atsparių – 29 %. Pavyzdžių, atsparių ir vid. atsparių vėžiui buvo 39 %

Lucerne resistance to Sclerotinia crown and stem rot

Lietuvos žemdirbystės institute 2008–2010 m. lauko ir laboratoriniais metodais tirtas 31 liucernos (Medicago spp.) veislės atsparumas vėžiui. Rezultatai, gauti laboratoriniais tyrimo metodais, tarpusavyje labai koreliavo. Buvo palygintas sėklų daigumas, naudojant oksalo rūgšties vandeninį tirpalą (koncentracija 30 mM) ir daiginant jas ant Sclerotinia trifoliorum grybienos, ir nustatyta stipri koreliacija (r = 0,774*, P < 0,01). Lyginant laboratorinius atsparumo nustatymo metodus su lauko tyrimu, taip pat gautos stiprios koreliacijos. Tarp sėklų dygimo ant S. trifoliorum grybienos ir liucernų atsparumo lauke nustatyta r = 0,842*, o tarp sėklų dygimo naudojant 30 mM koncentracijos oksalo rūgštį ir liucernos atsparumo lauke – r = 0,906*. Patvirtinta galimybė atrinkti atsparią liucernos medžiagą per trumpą laiką, naudojant itin paprastas priemones, kurios pagreitina liucernų atsparumo selekciją.The Sclerotinia crown and stem rot resistance of 31 cultivars of lucerne (Medicago spp.) were investigated in the field and laboratory experiments at the Institute of Agriculture in 2008-2010. Results obtained by laboratory methods strongly correlated. The strong correlation (r = 0.774*, P < 0.01) was calculated between seed germination test with water solution of oxalic acid (concentration 30 mM) and seed germination on the mycelium of Sclerotinia trifoliorum. Strong correlations also were calculated between results of laboratory tests and field experiment. Correlation coefficient r = 0.906* was calculated between seed germination test with water solution of oxalic acid and lucerne resistance in the field. Correlation coefficient r = 0,842* was calculated between seed germination on mycelium of S. trifoliorum and lucerne resistance in the field. Confirmed possibility to select resistant lucerne material during short time with small inputs should promote lucerne Sclerotinia crown and stem rot resistance breeding

Comparison of Productivity and Agro-Biological Traits of Alfalfa Populations Resistant to Mobile Al Grown on Acidic and Neutral Soils

To evaluate the agro-biological traits and select the promising populations of alfalfa under pedoclimatic conditions, field experiments were carried out in two locations of the Lithuanian Research Centre for Agriculture and Forestry (western Lithuania 55°70′ N, 21°49′ E and central Lithuania 55°23′ N, 23°51′ E). Eleven populations were established in acidic soil with a pH of 4.0 (experimental site I) and neutral soil with a pH of 7.0 (experimental site II). The productivity and agro-biological traits: fresh matter yield, dry matter yield, seed yield, stem thickness, and stem, leaf, and inflorescence weight of alfalfa populations were evaluated from 2019 to 2021. In the acidic soil, the populations 3056, 3132, 3130, and 3058 yielded more fresh and dry matter compared to the standard cultivar Birutė in the period from 2019 to 2021. In the acidic soil, populations 3131 and 3057 had a higher seed yield compared to the cultivar Birutė in 2019 and 2020, respectively. The 3086 population significantly differed in leaf weight compared to the cultivar Birutė. The cultivar Birutė and population 3132 were similar in stem thickness and fresh matter yield. In the neutral soil, population 3056 yielded more fresh matter compared to the cultivar Birutė

Diversity of Agro-Biological Traits and Development of Diseases in Alfalfa Cultivars during the Contrasting Vegetation Seasons

Alfalfa exhibits high adaptability to a range of environmental conditions. The aim of this study was to evaluate the agro-biological traits of alfalfa and select its most promising cultivars under different contrasting vegetation seasons. The field experiment was carried out at the Institute of Agriculture of Lithuanian Research Centre for Agriculture and Forestry. In 2016 and 2018, eleven alfalfa cultivars of different origin were established in the Endocalcari Epigleyic Cambisol. In the seasons of 2017–2018 and 2019–2020, the agro-biological traits of alfalfa cultivars were evaluated during winter; at the height of spring regrowth; before flowering at the three cuts; and during the fresh and dry matter yields; we also examined the development of diseases at the three cuts. The cultivar Birutė from Lithuania was distinguished by its wintering, its plant height at spring regrowth, its height before flowering, and its fresh and dry matter yields. The cultivar Timbale from France was distinguished by its wintering, spring regrowth, and its height before flowering. The cultivar Magnat from Romania was distinguished by its height before flowering and the fact that it was less damaged by downy mildew. The cultivars Jõgeva 118, Juurlu, and Karlu from Estonia were distinguished by their wintering and the fact that they were less damaged by diseases. The cultivar Eugenia from Italy was distinguished by the fresh and dry matter yields and the height before flowering