The creation of tetraploid beets
SummaryIn recent years trial fields were laid out with tetraploid families of the sugar beet varieties SX and SY, the fodder sugar beet varieties VA and VB and the fodder beet varieties VC (high content) and VD (low content).It appeared that the tetraploid beets are morphologically distinct from the diploid commercial varieties in leaf form, leaf development, form of the beet, tendency to bolt, size of the clusters and the number of seedlings per cluster.The beets of all the plots are washed, weighed and measured for dry matter, sugar and crude protein content and seed for stecklings is sown on a separate trial field.From the results it appears that there is a variation in the above-mentioned contents so that it seems possible to improve the material by selection. This also holds for the dry matter production which agrees with that of diploid commercial varieties.The investigations are being continued.
The yielding capacity of tetraploid sugar and fodder beets
Since the discovery of the use of colchicine in plant breeding, breeders have created tetraploid sugar and fodder beet. The results obtained were not very encouraging and therefore they soon proceeded to develop varieties containing triploids.At the Foundation for Agricultural Plant Breeding, Wageningen, polyploidy breeding was started in 1950. The initial material comprised two sugar beet varieties and five fodder beet varieties. By cytological examination of the aberrant individuals in the first and the second year after colchicine treatment, seed was obtained which produced a high percentage of tetraploids. In total 793 C2 families were tested on trial fields and from these 32% appeared to be better than the original diploid material.The breeders interested in the material were provided with seed and stecklings of all the families in the C1, C2 or C3 stage. With the distribution of this material the building up of tetraploid families at the Foundation for Agricultural Plant Breeding has been closed.SamenvattingSedert de ontdekking van de toepassingsmogelijkheden van eolchicine in de plantenveredeling zijn de kwekers begonnen met het tetraploid maken van suiker- en voederbieten. De verkregen resultaten waren niet erg hoopvol en reeds spoedig is men daarom overgegaan tot het creëren van rassen, waarin triploiden voorkomen.De S.V.P. is in 1950 begonnen met de polyploidieveredeling van 2 suikerbieten en 5 voederbietenrassen. Door de afwijkende bieten in hun eerste en tweede levensjaar nauwkeurig cytologisch te onderzoeken werd zaad verkregen, waarin een hoog percentage tetraploiden voorkwam. In een éénjarige zaadteelt werd van de C1 bietenzaad geoogst, dat op het proefveld werd uitgezaaid.In totaal werden 798 families in het C2 stadium onderzocht en hiervan bleek 32% beter te zijn dan de diploide uitgangsrassen. Van een jaargang werd van de beste families zaad op het proefveld uitgezaaid, het percentage van het aantal families, dat beter was dan het uitgangsmateriaal bleek iets groter.Van de overige families werd ook zaad geoogst; zij kwamen in het stadium C3 iets slechter naar voren dan de beste families.Aan de daarvoor in aanmerking komende kwekers zijn van alle families in het C1-, C2- of C3-stadium zaad en stekbieten afgestaan, waarmede de opbouw van de tetraploide rassen door de S.V.P. is afgesloten.
Effect of cutting management and nitrogen levels on biomass production and proximate quality of barley (Hordeum vulgare) in saline soil
A field experiment was conducted during the winter (rabi) seasons of 1997–1998 to 1999–2000 on an alluvial loamy sand saline soil at Hisar, to find out the effect of cutting management and nitrogen levels on biomass production and proximate quality of barley (Hordeum vulgare L). Dry forage yield of barley was 6.3% higher when harvested once at 50% heading compared with 2 cuttings at 60 days of growth and 50% heading. The total biomass was 3.8% higher when harvested for grain purpose compared to the treatment in which the crop was first harvested for forage at 60 days and subsequently left for grain purpose. However, no significant differences were observed in the yield equivalents of barley grown for grain purpose or green forage and grain. Application of N significantly increased the yield from 22.5 q/ha with 60 kg N/ha to 29.3 q/ha with 80 kg N/ha. The protein and mineral matter contents were higher in grains (9.2 and 4.7%) and fodder (5.3 and 10.3%) harvested at the early stages than 9.0 and 4.6% in grain; and 4.9 and 9.8% in fodder at the late stage. However, the fibre and lignin contents were more in fodder harvested at later stages. With increasing levels of N application, the mineral matter remained unaffected, while the crude protein and lignin contents increased and fibre decreased in both fodder as well as grain.