Ogburia, M. N., Adachi, T., Yabuya, T. (2000): Ovule dichotomy per locule of the trilocular pistil in cassava (Manihot esculenta): a useful abnormality for increased seedproduction? Plant Breeding , 119, 191
Authors:G. Kazinczi, J. Horváth, A. P. Takács, and D. Pribék
Crowley, R. H. and Buchanan, G. A. (1982): Variations in seedproduction and the response to pests of morningglory (Ipomoae) species and smallflower morningglory (Jacquemontia tamnifolia). Weed Sci. 30, 187
Authors:S. Anbumani, B. Chandrasekaran, T. Nadanassababady, and P. Rajendran
In a wet-seeded rice establishment system, it is feasible to raise dhaincha (Sesbania aculeata. W.) in alternate rows as an intercrop using a newly developed joint rice and green manure seeder. Intercropping dhaincha exclusively for in situ green manuring recorded a higher grain yield of rice (with green manure) than sole rice. Besides in situ green manuring, leaving every 20th row for seed production achieved not only the self manuring of the land, but also the self-production of green manure seed (dhaincha). Leaving dhaincha at narrow spacings (10th or 15th row) for seed production affected the growth, development and yield of rice in the adjacent rows. Within the total dose of fertiliser N, split dose of 25, 33, 21 and 21% at 20 days after sowing (DAS), at green manure incorporation (37 DAS), 55 DAS and 70 DAS were found to be the ideal method of N application, alleviating the temporary lock-up of N, if any, upon green manure incorporation. Thus, the sustainability of the green manure intercrop for in situ incorporation in the rice culture and of green manure seed production were proved by the study.
Authors:N. Bukhari, Iram Siddique, K. Perveen, I. Siddiqui, and M. Alwahibi
Synthetic seed technology is an alternative to traditional micropropagation for production and delivery of cloned plantlets. Synthetic seeds were produced by encapsulating nodal segments of C. angustifolia in calcium alginate gel. 3% (w/v) sodium alginate and 100 mM CaCl2 · 2H2O were found most suitable for encapsulation of nodal segments. Synthetic seeds cultured on half strength Murashige and Skoog medium supplemented with thidiazuron (5.0 μM) + indole-3-acetic acid (1.0 μM) produced maximum number of shoots (10.9 ± 0.78) after 8 weeks of culture exhibiting (78%) in vitro conversion response. Encapsulated nodal segments demonstrated successful regeneration after different period (1–6 weeks) of cold storage at 4 °C. The synthetic seeds stored at 4 °C for a period of 4 weeks resulted in maximum conversion frequency (93%) after 8 weeks when placed back to regeneration medium. The isolated shoots when cultured on half strength Murashige and Skoog medium supplemented with 1.0 μM indole-3-butyric acid (IBA), produced healthy roots and plantlets with well-developed shoot and roots were successfully hardened off in plastic pots containing sterile soilrite inside the growth chamber and gradually transferred to greenhouse where they grew well with 85% survival rate. Growth performance of 2 months old in vitro-raised plant was compared with in vivo seedlings of the same age. Changes in the content of photosynthetic pigments, net photosynthetic rate (PN), superoxide dismutase and catalase activity in C. angustifolia indicated the adaptation of micropropagated plants to ex vitro conditions.
The development of the maize hybrid Martonvásári 5 gave an enormous boost to the research institute a few years after its establishment. For decades afterwards the Martonvásár maize breeding team played a successful and dominant role both in Hungarian scientific life and in the field of practical results. In addition to breeding, great emphasis was placed on agronomic research, aimed at improving the success of maize production. Martonvásár was the first to introduce hybrid maize in Hungary and to elaborate field technologies and processing techniques for hybrid maize seed production.These successes came at a time when the need was felt to modernise the whole of Hungarian agriculture, so within a few years, the whole of the maize-growing area of the country was sown to Martonvásár hybrids.Fifty years after the registration of the hybrid Martonvásári 5, even though faced by strong international competition, Martonvásár still ranks first among Hungarian breeders, and occupies the 3
place compared with the multinational companies.
Studies were made on the fodder and seed production of ryegrass (Lolium perenne L.) using twelve treatment combinations with four levels of nitrogen (30, 60, 90 and 120 kg/ha/cut) and three levels of phosphorus (0, 50 and 100 kg P2O5/ha), laid out in a randomized block design with four replications. The mean of two years indicated that nitrogen at 120 kg/ha/cut increased the green fodder (834 q/ha) and dry matter yield (129 q/ha) significantly over the lower doses. After leaving the same crop for seed production during mid-March, nitrogen at the rate of 60 kg/ha gave the highest seed yield (7.61 q/ha). Beyond this dose the seed yield decreased drastically due to lodging. Phosphorus at the rate of 50 kg P2O5/ha gave 5% higher dry matter (99.6 q/ha) and 7.4% higher seed yield (7.26 q/ha) over the control.
Thirty-day-old plants of Lens culinaris (L.) Medic. cv. Pusa-6 were sprayed with 10-10, 10-8 or 10-6 M aqueous solutions of 28-homobrassinolide (HBR). Root length and nodule number per plant decreased, whereas the leaf nitrate reductase activity (E.C. 184.108.40.206) at 60, 90 and 120 days after sowing and the seed yield at harvest increased significantly in plants sprayed with either concentration of HBR. The values increased at first with an increase in the concentration of HBR but decreased with a further increase above 10-8M, which proved best for improving seed production.
In this review results are summarized
regarding the effect of virus infection on the physiological processes of
weeds. Through several host-virus model relations the biomass and
seed production, seed viability and germination, nutrient uptake,
drought-resistance and photosynthetic pigment content of healthy and virus
infected plants were compared. Because of their broad host range and high
genetic variability viruses cannot be used for biological weed control. It was
concluded that viruses unfavourably can influence physiological processes of
weeds. Therefore, they may contribute indirectly to the reduction of
competitive ability and population of weeds.
The integration of conventional plant breeding and plant transformation is necessitated by the fact that, prior to the gene technological phase, traditional breeding methods have to be used to develop agronomically valuable homozygous genotypes which can then be modified for a gene or genome segment by means of gene manipulation techniques. Once the genotype selected by means of conventional breeding has been transformed, traditional methods are again used to examine the agronomic properties of the lines developed from the transgenic plant and the stability of the transgenic variety, following the DUS criteria elaborated by UPOV. The seed production of genetically modified plant varieties must be safe and economical and the cultivation of the variety should contribute to the sustainable development of up-to-date crop production.