Some physical and physiological characteristics of Dalbergia cochinchinensis seeds collected from 4 soures in Thailand. It was found that seed length, width, thickness, weight, and seed germination showed highly significant differences within seed source, but there were no significant differences among seed sources. Seed length was found to be the most effective parameter to determine seed weight rather than seed width and seed thickness. On the other hand, coefficients of determination (r sup 2) of some physical characteristics of seed such as seed length and seed weight to seed germination showed high variation due to seed quality of individual trees. Light brown coat seeds gave higher germination than dark brown coat seeds for all individual trees. There were no significant differences in the germination responses of D. cochinchinensis after being subjected to various seed pretreatments and temperature conditions (30 deg C, 30 deg C/25 deg C and ambient dondition). When comparing seed sources in each temperature condition, it was found that seeds from Saraburi source gave the best germination capacity for all temperature conditions. It was found that the optimum temperature for germination of D. cochinchinensis was near 30 deg C. When comparing the effect of storage on the total germination and abnormal germinants, it was discovered that the seeds from Mahasarakam and Sakonnakorn sources showed higher rate of deterioration with reduced total germination and increased abnormality in germinants than those from Saraburi and Surin sources after 5-month storage at ambient condition.

We describe the Arabidopsis gene DAG2 encoding a Dof zinc finger protein and show that it is involved in the control of seed germination. An Arabidopsis mutant line with a T-DNA insertion in DAG2 isolated by reverse genetics produces seeds that are substantially more dependent than the wild type on the physical stimuli-light and cold treatment-that promote germination. Mutant dag2 seeds also are less sensitive to the germination-promotive effect of gibberellins, because a 10-fold higher amount of gibberellins is needed to restore germination when endogenous gibberellin biosynthesis is blocked. The seed germination characteristics of the dag2 mutant are opposite to those of dag1, a knockout mutant of another Dof gene (DAG1) that we showed previously to be involved in the control of seed germination, and are similar to those of plants that overexpress DAG1. The promoter of the DAG2 gene is active specifically in the vascular system of the mother plant but not in the embryo, and segregation analysis indicates that the effect of the dag2 mutation is maternal. Both characteristics are in common with DAG1; additionally, the DAG1 and DAG2 proteins share high sequence homology and an identical zinc finger domain. These data suggest, and the germination phenotype of the double mutant is compatible with, a model whereby the zinc finger proteins DAG1 and DAG2 act on a maternal switch that controls seed germination, possibly by regulating the same gene(s).

Vertebrates are important seed dispersers for many plants. In addition to transport of seeds, ingestion often affects the proportion or rate of seed germination. We present one of the first studies comparing the effects of different waterbird species on the seeds of a subcosmopolitan pondweed, Potamogeton pectinatus. We also present the first comparison of the effects of digestion by ducks (mallard Anas platyrhynchos, shoveler A. clypeata and wigeon A. penelope) and physical-chemical "simulation of digestion" on pondweed seed germination. In two experiments differing in the length of the preceding stratification period, two to three individuals per duck species were force-fed 150 seeds each. Average retrieval, total germination and germination rate did not differ significantly between duck species. Germination rate was higher for duck ingested seeds, intermediate for scarified seeds (i.e. after mechanical removal of the epicarp+mesocarp) and lowest for the controls and acid treated seeds, independently of the length of the stratification period. Total germination, however, did not differ significantly among duck-ingested, scarified, control and acid treated seeds. Consequently the changes in germination rate after ingestion by ducks seem related to the grinding treatment in the gut and unrelated to exposure to acidic conditions. The co-existence of ingested and uningested seeds within a given seed cohort will increase the diversification of seed germination patterns, which can favour the colonisation of habitats characterised by unpredictable environmental conditions | Peer reviewed

Vertebrates are important seed dispersers for many plants. In addition to transport of seeds, ingestion often affects the proportion or rate of seed germination. We present one of the first studies comparing the effects of different waterbird species on the seeds of a subcosmopolitan pondweed, Potamogeton pectinatus. We also present the first comparison of the effects of digestion by ducks (mallard Anas platyrhynchos, shoveler A. clypeata and wigeon A. penelope) and physical-chemical “simulation of digestion” on pondweed seed germination. In two experiments differing in the length of the preceding stratification period, two to three individuals per duck species were force-fed 150 seeds each. Average retrieval, total germination and germination rate did not differ significantly between duck species. Germination rate was higher for duck ingested seeds, intermediate for scarified seeds (i.e. after mechanical removal of the epicarp+mesocarp) and lowest for the controls and acid treated seeds, independently of the length of the stratification period. Total germination, however, did not differ significantly among duck-ingested, scarified, control and acid treated seeds. Consequently the changes in germination rate after ingestion by ducks seem related to the grinding treatment in the gut and unrelated to exposure to acidic conditions. The coexistence of ingested and uningested seeds within a given seed cohort will increase the diversification of seed germination patterns, which can favour the colonisation of habitats characterised by unpredictable environmental conditions. | Peer reviewed

Effects of physical treatment in combination with dipping in potassium nitrate (i) no treatment: K0, (ii) scarification of seed using sand paper: K1; (iii) dipping of seed in 0.1 percent KNO3 for 24 hours: K2; (iV) (K1 + K2): K3; (v) K1 and dipping in 0.3 percent KNO3 for 24 hours: K4; (vi) K1 and dipping in 0.5 percent KNO3 for 24 hours: K5; and (vii) K1 and K2 and dipping in warm water for 3 minutes on seed germination and seedling growth of Arenga were investigated in field experiment. It was found that K1 treatment gave better seed germination than K2 treatment. Combination found of K1 and K2 tended to improve both germination of seeds and growth of seedlings | Penelitian dilaksanakan di Kebun Akademik dan Laboratorium Ilmu dan Teknologi Benih Jurusan Budidaya Pertanian, Fakultas Pertanian UNTAD. Penelitian ini berlangsung mulai Juni hingga November 2001. Penelitian dilaksanakan dalam bentuk percobaan yang disusun secara rancangan acak lengkap (RAL) satu faktor, yaitu: K0 (tanpa perlakuan), K1 (mengikis punggung benih), K2 (perendaman kalium nitrat 0,1 persen selama 24 jam), K3 (K1 + K2), K4 (K1 + perendaman kalium nitrat 0,3 persen selama 24 jam), K5 (K1 + perendaman kalium nitrat 0,5 persen selama 24 jam), K6 (K1 + K2 + perendaman dalam air hangat selama 3 menit). Perlakuan diulang 3 kali sehingga terdapat 7 x 3 = 21 unit percobaan, dan setiap unit percobaan digunakan 10 butir benih Aren sehingga jumlah benih yang digunakan adalah 21 x 10 = 210 butir. Petak perlakuan di tempat penelitian disusun secara acak, dengan tabel angka teracak. Hasil penelitian menunjukkan perlakuan fisik (mengikis punggung benih) dapat meningkatkan perkecambahan benih Aren, yang lebih baik dari pada perlakuan perendaman kalium nitrat 0,1 persen selama 24 jam. Bila kedua perlakuan tersebut dikombinasikan maka dapat lebih mempercepat perkecambahan benih Aren dan pertumbuhan kecambah

Survey of the occurrence of fungi and mycotoxins in wheat and flour has been performed on samples of two wheat varieties, Nevesinjka and Jarebica in Pirot, Serbia (Serbia&Montenegro). The lower severity of fungal infestation was established ranging from 0.79 to 0.88 fungus per kernel. Attributed to the lower severity, only few mycopopulations were determined belonging to the following genera: Alternaria, Fusarium and Penicillium. Ochratoxin A (OA) contaminated 75% of the samples while aflatoxins B1 (AB1) and G1 (AG1) and zearalenon were not detected. Biological quality of wheat was controlled by germination and germination energy. Physical properties of wheat samples were investigated (test weight, 1000 kernel weight, granularity) as well as chemical properties, that included measuring moisture, extraction, ash content and protein content. Dough rheology was controlled measuring wet gluten content (ranging from 34 to 37%), swelling capacity of gluten after Berliner, and swelling of gluten in the solution of salt for 24 h.

The effects of seed cleaning and handling on soybean seed germination and physical integrity were determined with changing seed moisture content (m.c.). In addition, storage behavior of seed and loss of storability caused by damage resulting from free-fall from different heights were determined. Six lots of the variety "MACS-13" at three different m.c.'s were passed through a vertical bucket elevator, cleaner with grader, and gravity separator and evaluated for mechanical damage, germination, and vigor index. The storage behavior of the lots, at different stages of processing, was studied by performing an accelerated aging test. The effect of free-fall on quality of the seed was studied by dropping six seed lots from four different heights on to cement and galvanized iron floors. The vertical bucket elevator significantly decreased germination and increased splits and seed coat damage. The seed lots at 12% m.c. (dry basis), suffered less loss in seed quality than the lots at 10% or 11% m.c. The storage quality of seed, as predicted by the accelerated aging test, at 12% m.c. was also better than the lots at 10% or 11% m.c. A free-fall of soybean seed from different heights on to the cement floor resulted in greater loss in quality than when dropped on to the galvanized iron floor.

The broad objective of this research was to define the role of warm (greater than or equal to 15 degrees C) stratification in breaking dormancy in seeds with stony endocarps that require warm-plus-cold (approximately 0 degrees -10 degrees C) stratification for germination. This question was addressed using seeds (true seed + endocarp, hereafter called seeds) of Empetrum hermaphroditum. Only 2-5% of freshly matured seeds collected in September and October at five sites in Sweden germinated in light at daily alternating temperature regimes of 15 degrees/6 degrees, 20 degrees/10 degrees, and 25 degrees/15 degrees C. Dormancy was not due to impermeability of the stony endocarp surrounding each seed, and embryos did not grow prior to radicle emergence. Thus, seeds did not have physical, morphological, or morphophysiological dormancy. Long periods of either cold stratification (20 or 32 wk) or warm stratification (16 wk) resulted in a maximum of 22-38 and 10% germination, respectively, in light at 25 degrees/15 degrees C. After 12 wk warm stratification plus 20 wk cold stratification, 83-93% of the seeds germinated in light at the three temperature regimes. For a cold stratification period of 20 wk, germination increased with increase in length of the preceding warm stratification treatment. Gibberellic acid (GA3) promoted germination of 77-87% of the seeds. Based on dormancy-breaking requirements and response to GA3, 62-78% of the seeds had intermediate physiological dormancy; the others had nondeep physiological dormancy. Contrary to suggestions of several other investigators that warm stratification is required to make the endocarp permeable to water via its breakdown by microorganisms, our results with E. hermaphroditum show that this is not the case. In this species, warm stratification is part of the dormancy-breaking requirement of embryos in seeds with intermediate physiological dormancy.

Thesis | The objective of this study was to determine the effect of the environment on the quality and yield of seed from different seed lots. Localities with different soil types, soil structures and climates were chosen to grow seed lots of the soybean (Glycine max L. Merril) variety Prima. After harvesting by hand, the seed was analysed for oil, protein and mineral content. Physical quality, germination and vigour tests were also done. There were big differences in the growing conditions and precipitation. Rainfall varied from a high of 956mm for the Komatipoort locality to a low of 149mm for the Delmas locality. The percentage defects varied from 0.5% for Delmas to 78% for Komatipoort and the germination percentage from 94% for Klerksdorp to 16% for Komatipoort. Suitable temperatures and rainfall lead to the infection ofthe disease Phomopsis longicol/a atthe Komatipoort locality. This was the reason for poor germination results and high percentage defects in the seed. Vryheid had the highest protein percentage of 38.53% and Delmas the lowest of 33.34% The harvested seed was planted at Greytown first on the Redgates and Chaileyfarm in a randomized block design in orderto determine germination, vigour and yield for seed from different seed lots multiplied in different soil types and climatic conditions, and now planted under similar climatic conditions. The analyses and comparisons in terms of leaf area index at the early flowering (R2) stage, plant height at harvest mature (R8) stage, pod height at R8 stage and eventual yield, did not reveal any significant differences (P=0.05). No significant differences were recorded for seed yield Yield. The average yield of the Chailey locality however was 1021 .9 kg/ha higher than the average yield ofthe Redgates locality. Growth conditions did dominate the effect of different seed lots. Poor germination and stand also had very little effect on seed yield as demonstrated by the Komatipoort treatment. Although plantpopulation was 150000 plants per hectare lower than the average for both trials, final seed yield were not significantly different (P=0.05) Therefore plant population had no influence on the yield. The author conclude thatfor soil types, soil structures and climatic conditions typical of this study, no effect for seed lot on yield could be demonstrated