Higher Number Of Seeds Research Articles

INVESTIGATION ON THE INHERITANCE OF THE TRAITS NUMBER OF SEEDS PER PLANT AND 1000 KERNEL WEIGHT IN SUNFLOWER HYBRIDS

The investigation was carried out during 2013 – 2016 at Dobrudzha Agricultural Institute – General Toshevo, Bulgaria. The traits number of seeds per plant and 1000 kernel weight are of primary importance; they influence the increase of yield. This investigation included 8 hybrid combinations and the parental forms involved in the crosses. The additive-dominant relations of the traits were analyzed through the ratio between the parameters d/a. In crosses 217А x 88R, 813A x 97R, 813A x 100R, and 2003A x 98R, super dominance according to the parental forms was observed. Higher number of seeds per plant and 1000 kernel weight were obtained in these hybrid combinations in comparison to the parental forms. Incomplete dominance of these traits was found in combinations 217 x RW666 and 217 x 138R.

Floral visits of the wild bee, <i>Lithurgus atratus</i>, impact yield and seed germinability of okra, <i>Abelmoschus esculentus</i>, in Sri Lanka

Bee-pollinated crops in landscapes with a low abundance of bees suffer from insufficient pollination. The present study investigates the effect of wild bee pollination on fruit and seed production in okra, Abelmoschus esculentus (L.) Moench. The study was conducted in a home garden, where an okra field was established for three pollination trials each to include 40 okra plants. For each trial, three sets of 25 flower buds were selected and tagged. One set was covered to deter bees, another set was kept open to enable bee visits and the other set was cross-pollinated by hand. Of the two species of bees, Tetragonula iridipennis (Smith) visited flowers for nectar while Lithurgus atratus Smith collected and carried pollen grains. The period of stigma receptivity and pollen availability coincided with the highest activity of L. atratus from 10.00 a.m. to 12.20 p.m. Bee-pollinated flowers had significantly enhanced okra pod length and diameter, seed number and seed germinability compared to the trial with flowers covered to deter bees. Hand pollinated flowers also produced significantly longer pods and a higher number of seeds with higher germinability. Although there was no significant difference in pod length and diameter and seed number between hand pollination trial and bee-pollinated trial, germinability of bee-pollinated seeds was significantly higher. Present study highlights the importance of the wild bee, L. atratus to enhance pod size, seed number and seed germinability in okra in Kurunegala, Sri Lanka.

GENETIC DIVERSITY OF RAPESEED (Brassica napus L.) GENOTYPES IN BANGLADESH

Genetic diversity in thirty eight traditional rapeseed genotypes was studied under favorable condition through Mahalanobis D2 statistic for yield and yield contributing characters. The genotypes were grouped into five clusters. The inter-cluster distances were higher than intracluster distances indicating wider genetic diversity among the clusters. The intra-cluster distances were lower in all the cases reflecting homogeneity of the genotypes within the clusters. Among the different cluster the genotypes of the cluster IV, III and I included were taller plant. The genotypes in the cluster III and IV had large size raceme. The genotypes in the cluster IV, III and V exhibited comparatively higher number of siliqua per raceme. Longer siliqua was noticed for the genotypes in the cluster III, IV and I. Higher number of seeds per siliqua noticed in clusters I, II and III. The genotypes of the cluster I and II produced bold size seed. The genotypes in the cluster V and I had high harvest index. The genotypes of the cluster III and I produced high seed yield per plant. Among the different cluster, the cluster III included the genotypes which had high yield, higher number of seeds per siliqua, longer siliqua, siliqua number per raceme and high plant height. Moreover these cluster displayed wide divergence with the genotypes of cluster V. The genotypes of the cluster V had the highest harvest index therefore selection of the parental material for crossing program for improvement of yield in rapeseed is suggested from these two clusters.

Keragaman dan Pengelompokan Sumber Daya Genetik Kacang Tunggak [Vigna unguiculata (L.) Walp.

Cowpea [Vigna unguiculata (L.) Walp.] is a legume that tolerant to drought and acid soil, that is prospective for development in sub-optimal area. A total of 150 cowpea accessions were grown at Muneng Research Station (Probolinggo) in dry seasson of 2014, using a randomized block design, with two replications. Each accession were planted along two rows of 4 m. The accession was varied for the qualitative and quantitative traits. Most of the accession had ovate leaf shape, flower color purple, cream color of mature pod, and seed color brown to yellowish. Seed yield had a high phenotipic and genotypic coefficient of variation and genetic advance. Low of phenotipic and genotypic coefficient of variation were shown on days to 50% flowering and days to physiological maturing. Characteristics of cowpea accessions for eight variables 64.2% can be explained by three factors. The first factor relates to seed yield component (number of fertile nodes, number of branches, and seed weight), second factor associated with plant age (date of flowering and harvesting), and the third factor is the supporting factors (plant height, pod length, and number of seeds per pod). Accessions of cowpea could be divided into three groups. Date of flowering and harvesting were a determinant variable discriminant function. Group I consisting 70 accessions dominated by accessions with early maturity, medium plant height, long pods, high number of seeds per pod and high seed yield. Group II consisting of 47 accessions with moderate maturity, short plants, short pods, low number of seeds per pod and low seed yield. Group III consisting of 33 accessions was characterized by moderate maturity, high plant, short pods, high number of seeds per pod and high seed yield.

Uticaj plodoreda na rezerve semena korovskih biljka u zemljištu

Crop rotation, soil cultivation and weed control measures are in direct correlation with the content of the weed seed bank in the soil. Knowing the weed seed bank and the dynamics of the weed emergence is the basis for planning and implementing the measures for effective weed control. The research was carried out on the plots of the long-term stationary experiment 'Plodoredi' of the Institute of Field and Vegetable Crops in Novi Sad. During August of 2014, following the soybean harvest, the soil from the plots under different cultivation systems was sampled: soybean monoculture and 3-field (soybean, wheat, corn). Two methodological procedures were used to evaluate the reserve of seeds in the plough layer and the under plough soil layer. The physical extraction of seeds has determined the total content of weed species in the seed bank, while seed germinarion was used to determine which of the observed species are capable of germinating in the following period. The method of physical extraction has determined that the highest number of seeds was present in the soil samples from the soybean monoculture, in the depth layer of 15-30 cm. The under plough soil layer was characterized by a lower number of seeds, in both variants. In the study of germination, which was conducted under controlled conditions 18 months after the sampling, the best seed germination was recorded for the seeds of Ambrosia artemisiifolia L., Chenopodium hybridum L. and Chenopodium album L.

Evaluation of Promising Mung Bean Mutants Against Foot and Root Rot, Cercospora Leaf Spot and Yellow Mosaic Diseases

The experiment was conducted to evaluate disease resistant mutants against foot and root rot, Cercospora leaf spot and mung bean yellow mosaic disease under natural epiphytotic condition, 9 mutants collecting from the Bangladesh Institute of Nuclear Agriculture were used in this experiment. Among the mutants, MBM-07(S)-2 was found resistant against the foot and root rot disease followed by MBM-347-13, MBM-390-94-Y and MBM-656-51-2. Most of all plants of each plot were attacked by Cercospora leaf spot of mung bean. The highest yellow mosaic disease incidence 84.76% was recorded in MBM-80 (LCAL) and the lowest 20.00% in MBM-527-114 followed by MBM-07-Y-2 (30.00%) and MBM-427-87-3 (33.67%). The highest yellow mosaic disease severity 26.84% was observed in MBM-80 (LCAL) and the lowest 0.38% was observed in MBM-527-114 followed by MBM-656-51-2 (1.04%) and MBM-427-87-3 (1.63%). The highest number of seeds per pod was counted in MBM-07-Y-1 and the highest 1000 seed weight was observed in BARI Moog-6 (50.00 gm) followed by MBM-527-114 (45.67 gm). The highest grain yield 204.44 kg was recorded in MBM-07-Y-1 followed by MBM-390-94-Y (186.66 kg). MBM-07(S)-2, MBM-07-Y-2, MBM-07-Y-1 and MBM-527-114 mutants showed less disease incidence and severity for foot and root rot, Cercospora leaf spot and mung bean mosaic disease and gave better yield than other mutants.

EFFECTS OF GROWING CONDITIONS ON CROSSING SUCCESS IN DIFFERENT POTATO(Solanum tuberosum L.)CROSSES

This study was carried out to determine the effect of growing conditions underdifferent altitudes on seed production in different potato crosses in Tokat Provinceof Turkey in 2015. Plants were grown and crosses were made in open field or nethouse in Tokat location (altitude 600 m asl.), open field or net house in Artovalocation (altitude 1200 m asl.), or controlled polycarbonate greenhouse. Fifteendifferent crosses were made between 12 parent cultivars. Production of hybridpotato seed was considered “crossing success”. Results showed that parentcultivars and cross combinations affected crossing success and no seeds wereproduced from some combinations while some combinations produced abundantseeds. The highest number of seeds were produced in controlled polycarbonategreenhouse, whereas very low amount of seeds were produced under low altitude(600 m asl.) open field conditions. Polycarbonate greenhouse produced 47.3% ofall seeds, while low altitude net house produced 19.8%, high altitude open fieldproduced 15.8%, high altitude net house produced 13.6% and low altitude openfield produced 3.5%. It was concluded that for a high crossing success, potatocrossing should be made by controlled polycarbonate greenhouse conditions and 23C0 day / 17 C0 night temperatures produced more hybrid seeds.

Preliminary Report: Effects of black mustard allelopathy on the fitness and life history strategies of buffalo gourd in southern California

Abstract. The allelopathic compounds secreted into the soil by Brassica nigra (L.) W. D. J. Koch (black mustard) serve to reduce seed germination rates and plant fitness in nearby species. As such, B. nigra shares in an amensalistic relationship with most of the species within range of its allelopathic interference. However, Cucurbita foetidissima (buffalo gourd) is a native species in southern California that has managed to persist within and around areas invaded by B. nigra. We hypothesized that increased proximity to B. nigra would negatively impact C. foetidissima fitness and alter life history strategies. We found that C. foetidissima growing in close proximity to B. nigra had smaller fruit volume, a lower number of seeds per fruit, lower dry seed weight, a higher number of seeds per cubic centimeter, and a higher number of seeds per gram of fruit than C. cucurbita that grew outside of the allelopathic range of B. nigra. The reproductive strategy of C. cucurbita also appeared to change from K-selecti...

Evaluation of sunflower (Helianthus annuus L.) single cross hybrids under heat stress condition

ABSTRACTSunflower is an important oilseed crop, which shows susceptibility to heat stress. In this study, 63 single cross hybrids were evaluated under heat stress condition for 2 years and compared with the two commercial hybrids. Genotype and genotype × environment (GGE) was used to differentiate single cross hybrids on the basis of multiple traits. GGE biplot showed that several single cross hybrids had higher seed yield potential than standard check. Moreover, seed yield per plant (SYP) was related to pollen viability percentage, showing that achene yield was the product of high gametophytic fertility under heat stress. Hybrids having high seed yield potential under heat stress had lower cell membrane injury. GGE biplot for SYP and its components showed that single cross hybrids were characterized into two major groups. Group I was further characterized into two sub group. Group Ia included hybrids with high 100-SW, while group Ib had the hybrids with high number of seeds per head and head diameter. Group II had the hybrids with high kernel weight and kernel to seed ratio. The hybrids could be recommended according to their potential utilization in the seed industry.

Standardization of organic module for sustainable productionof fenugreek (Trigonella foenum graecum L.)

A field experiment on the standardization of organic module for production of fenugreek (Trigonella foenum graecum L.) was conducted during rabi season of 2009-10 to 2012-13 (four years). The experiment was laid out in Factorial Randomized Block Design (RBD) consisting of three organic modules (M1, M2 and M3) and two fenugreek varieties (AFg-1 and RMt-305) with four replications. Findings of present study showed significant differences among the performance of different organic modules tested for two fenugreek varieties. Organic module-1 (M1)comprising of soil application of vermi-compost @5 t/ha+ foliar spray of 5% garlic extract @ 2.0 kg/ha + 2% neem oil @ 5 litre/ha+ soil application of neem cake @150 kg/ha and Trichoderma @ 2.5 kg/ha, seed treatment with Rhizobium @100 ml/kg seed, PSB @ 100 ml/kg seed and Trichoderma @10 g/kg seed exhibited earliest seed germination and maximum plant height (5.78, 19.69, 43.39 and 50.97 cm) at 30, 60, 90 DAS and at harvest, respectively with maximum number of branches (6.76/ plant), number of pods (42/ plant), number of seeds (16.01/ pod), highest grain yield (1515.21 kg/ha), gross return (100004) and net returns (66741) in fenugreek crop. Similarly significant differences were recorded in the performance of fenugreek varieties under different organic modules and the highest plant height, maximum number of branches and pods per plant, highest number of seeds per pod with maximum grain yield (1568.36 kg/ha), gross returns (103512), net returns (71399) with higher B:C ratio (2.22) were recorded in fenugreek variety AFg-1 than variety RMt-305. Cultivation of fenugreek variety AFg-1 with the application of Module-1 exhibited maximum values for all the growth parameters, yield attributing characters, maximum grain yield, net returns with improvement in soil organic carbon % (OC) and soil fertility (available N, P and K) after 4 crop cycles. Hence, variety AFg-1 is recommended to grow organically with the application of Module-1 (M1) under semi-arid environmental conditions

Flowering and fruiting behavior of velvet apple

The study was conducted at three upazilla of Patuakhali during the period from the 1st February, 2013 to the 31st July, 2013 to evaluate the flowering and fruiting behavior of velvet apple germplasm. Twelve velvet apple germplasm were selected from three locations (DD 01, DD 04, DD 06, and DD 09 from Dumki; DD 02, DD 05, DD 08 and DD 10 from Mirzaganj; DD 03, DD 07, DD 11 and DD 12 from Patuakhali sadar upazilla) by field survey. The age of plant varied from 10 to 25 years having satisfactory growth and good health. A lot of variations in different parameters were observed among the germplasm. Flowering season started from 22 February and continued up to 20 April. Percentage of fruit setting ranged from 65.15 % to 92.26 % in DD 07 and DD 01, respectively. Required time for fruit maturation ranged from 116 days (DD 01) to 129 days (DD 07). Single fruit weight varied from 198.10 g (DD 12) to 238.90 g (DD 01). The highest number of seeds (8) was found in DD 07 while DD 01 was seedless. The length and diameter of fruit ranged from 6.72 cm (DD 07) to 8.04 cm (DD 01) and 6.09 cm (DD 07) to 7.27 cm (DD 01), respectively. The maximum edible portion (87.33 %) was recorded in seedless germplasm DD 01, while it was the lowest (42.00 %) in DD 07.Asian J. Med. Biol. Res. December 2015, 1(3): 660-669

Taxonomic studies of the genus Tephrosia Pers. (Papilionaceae) in Nigeria

The relationship between eleven Tephrosia species occurring in Nigeria was examined using a number of taxonomic tools. Fresh and herbarium specimens were used for this purpose and methods followed conventional taxonomic practice. Although the species occur in savanna ecosystems, herbarium collections revealed an abundant distribution in the southern part of Nigeria. Morphometric studies revealed that four quantitative characters viz: leaflet length, lamina length, fruit length and pedicel length can be used to delimit members of this genus. Based on the cluster analysis using average linkage within group, the closest species are T. leptostachya and T. purpurea with the shortest distance measure (0.713). T. linearis has the smallest leaflet, in length and width. Further morphological studies also showed that T. vogelii has the largest pod while T. barbigera has the highest number of seeds per pod. Generally, the species have very short petiolule ranging between 0.2cm and 0.3cm in length, on the average. Foliar micro-morphological studies also showed that the species generally possess polygonal cells with straight to curved anticlinal walls and anisocytic stomata types while pollen studies revealed tricolporate pollen grains to be predominant within the taxa. Although, the present study has added to the existing information regarding Tephrosia species, it also suggests further research to ascertain its taxonomic position within the Papilionaceae.

Genetic diversity of resynthesized Brassica napus lines from SW China assessed by main agronomic traits and SSR markers in comparison with common B. napus lines

Genetic diversity of 96 resynthesized (RS) Brassica napus lines and 25 common (CM) lines were evaluated in present study based on eight main agronomic traits and 315 polymorphic SSR markers. The RS lines were developed through interspecific hybridizations between a vegetable cabbage (B. oleracea L. ssp. alboglabra Bailey) and a number of landraces in B. rapa L. ssp. chinensis and campestris from Southwestern regions of China. The CM lines include 10 elite lines bred in our own Sichuan Agricultural University, 9 elite lines from domestic research institutes in China and 6 exotic spring rapeseed lines from Germany and Canada. The investigated main agronomic traits include plant height, first branch height, main inflorescence length, number of primary branches, siliqua length, seeds per siliqua, siliqua density on the main inflorescence and 1000-seed weight. The observed agronomic traits exhibited a remarkable difference between the RS lines and the CM lines. Large variations were observed in main agronomic traits in the RS and CM lines. A number of salient RS lines were identified, showing variable unique agronomic traits, such as extremely long siliqua length, large 1000-seed weight, high number of seeds per siliqua and high siliqua density, etc. Clustering analyses were made based on both agronomic traits and SSR markers. The UPGMA dendrogram based on the main agronomic traits revealed a major differentiation between the RS lines and the CM lines. The UPGMA dendrogram based on SSR markers clearly distinguished the two main groups of RS lines and CM lines. Large variations and diversities were observed among the RS lines and the CM lines. Big variations were also observed within most of the RS and CM subgroups. We conclude that the RS lines are markedly different from the common (CM) B. napus lines in the study. Large diversity exists among the RS lines and the CM lines. These RS lines could be a valuable source of new germplasm for rapeseed breeding and genetic studies. It is also suggested that the resynthesis of novel B. napus types through interspecific hybridizations with the diverse indigenous B. oleracea and B. rapa sources could be an efficient way to broaden the genetic basis of B. napus L.

Cross compatibility in interspecific hybridization of eggplant, Solanum melongena, with its wild relatives

The eggplant, Solanum melongena L., is one of the most important warm season vegetable crops grown in India. In the present study, interspecific hybridization was carried out involving thirteen cultivated genotypes of eggplant and four wild Solanum species (Solanum incanum, S. aethiopicum, S. integrifolium and S. indicum). The cultivated genotypes were used as female parents and wild species as pollen parents in different cross combinations. The crossability relationship of S. melongena genoptypes with the wild species was determined by occurrence of fruit set (%), number of seeds per fruit and germination (%) of F1 seed. The mean fruit set was maximum for DBSR-91 (41.25%) followed by DBR-G-190 (37.91%) and NDB-25 (32.08%). The maximum number of seeds per fruit (266.92) was obtained in DBR-G-190 followed by Pusa Uttam (101.42) and Sel-91-2 (92.00). The mean value of highest germination (%) of F1 seed was observed for DBSR-91 (41.58%) followed by Pusa Uttam (40.25%) and Sel-91-2 (35.50%) when crossed with wild species. The maximum fruit set (80%) was recorded in cross DBSR-91×S. aethiopicum followed by Pusa Bindu×S. aethiopicum (75%) and NDB-25×S. aethiopicum (75%). The highest germination of F1 seed (71%) was recorded in three cross combinations, Pusa Uttam×S. aethiopicum, Sel-91-2×S. aethiopicum, DBR-G-190×S. aethiopicum. The highest number of seeds per fruit (754) was recorded in DBR-G-190×S. incanum followed by DBSR-52×S. incanum (226.6), DBR-G-190×S. aethiopicum (206). Among the four wild species, S. incanum was found highly crossable with the cultivated S. melongena genotypes. Interspecific crosses reported in this study will be used in transferring desirable traits in different genetic backgrounds of cultivated S. melongena.

English

Investigating phenotypic variation in fruit traits constitute an important base for biodiversity assessment and domestication. The present study was carried out in order to assess the diversity of phenotypic traits of Carapa procera fruits. A total of 430 fruits were collected on 43 trees, and their surface aspect, length, width, weight, number of carpels and number and weight of seeds were recorded. Hierarchical clustering and principal component analysis were used firstly on the fruit variables to determine morphotypes and secondly on the morphotypes variables to relate their traits to tree characteristics. Analyses of variance were performed to test for differences in phenotypic traits between morphotypes. Three morphotypes of C. procera fruits were identified: Morphotype 1, morphotype 2 and morphotype 3 including crested fruits, goffering fruits and smooth fruits, respectively. Morphotype 1 and 2 grouped the largest and heaviest fruits, while the morphotype 3 grouped the smallest and lightest ones. The highest number of seeds per fruit was found in morphotype 2, whereas morphotype 3 had the lowest number. Morphotypes were not related to the tree size. Morphotype 2 provides the highest value traits and represents the best choice for plantation purposes. Key words: Biological diversity, morphological traits, wild fruits, Carapa procera, oil tree, Burkina Faso.

Effect Of Soil Waterlogging Stress On The Physiological Performance Of Seeds And On The Productivity Of Rye Plants

The objectives of this study were to evaluate the effect of waterlogging on seed physiological performance and plant productivity in rye. Our study consisted of three treatments: 1) no waterlogging, 2) a single waterlogging period, and 3) double waterlogging period. Plant productivity was evaluated from the number of spikes per plant, the number of seeds per plant, the number of seeds per spike, and seed yield. Seeds were exposed to a germination test and seed physiological quality was evaluated from the seed germination rate, initial germination rate, germination speed index, electric conductivity, shoot length, primary root length, shoot dry matter and primary root dry matter, and weight per 1000 seeds. The seeds derived from plants not exposed to waterlogging showed a higher germination rate in a shorter period of time and higher germination speed index than those derived from plants that were exposed to waterlogging; however, the weight per 1000 seeds was lower and seedlings had longer shoots and primary roots. The plants that were not exposed to waterlogging had a higher number of spikes per plant, higher number of seeds per plant, higher number of seeds per spike, and better seed yield per plant. Therefore, it was concluded that waterlogging has a negative effect on seed physiological performance in rye and that plant productivity is reduced under long-term waterlogging.

Response of bio-regulators to yield and quality of Indian mustard (Brassica juncea L. Czernj. and Cosson) under different irrigation environments

A field study was conducted during rabi seasons of 2008 and 2009 to evaluated of productivity of Indian mustard (Brassica juncea L.) by foliar spray of bio-regulators under different irrigation environments. Amongst treatments, the application of sufficient irrigation water (four irrigations) recorded the highest number siliqua per plant, higher number of seeds per siliqua, 1000 seed weight and yields as compared to all other irrigation treatments. Results show that an increased in seed yield of 92.40 and 39.37 % under sufficient irrigation and limitedwater condition in 2008 and 93.34% and 40.31% in 2009, respectively over deficient irrigation conditions, foliar sprays of 100 ppm thioglycollic acid at initiation of branching were recorded highest yield attributes and yields. Similarly, 500 ppm of thiourea at initiation of branching and flowering stages also gave second best highest yield attributes and yields as compared to all other bio-regulators spray stages. However, bio-regulators sprays were not recorded any significant effect on oil and protein content. The results were concluded that economic feasibility to improve productivity of Indian mustard with four irrigations levels and sprays of 100 ppm thioglycollic acid and 500 ppm of thiourea at initiation of branching and flowering stages under hyper arid environment.

Assessment of genetic diversity among faba bean genotypes using agro-morphological and molecular markers

Forty faba bean (Vicia faba L.) genotypes were evaluated for their agro-morphological performance and molecular diversity under Central Region of Saudi Arabia conditions during 2010–11 and 2011–12 seasons. Field performance results showed that faba genotypes exhibited a significant amount of variation for their agro-morphological studied parameters. Giza40 recorded the tallest genotype (139.5cm), highest number of seeds per plants (100.8), and the highest seed yield per plant (70.8g). The best performing genotypes were Giza40, FLIP03-014FB, Gazira1 and Goff1. Genetic variability among genotypes was determined using Sequence Related Amplified Polymorphism (SRAP) and Amplified Fragment Length Polymorphism (AFLP) markers. A total of 183 amplified fragments (alleles) and 1758 polymorphic fragments (bands) in SRAP and 202 alleles and 716 bands in AFLP were obtained using six SRAP and four AFLP primer combinations respectively. Polymorphism information content (PIC) values for AFLP and SRAP markers were higher than 0.8, indicating the existence of a considerable amount of genetic diversity among faba tested genotypes. The UPGMA based clustering of faba genotypes was largely based on origin and/or genetic background. Result of cluster analysis based on SRAP showed weak and not significant correlation while, it was highly significant based on AFLP analysis with agro-morphological characters (r=0.01, p>0.54 and r=0.26, p<0.004 respectively). Combined SRAP and AFLP markers proved to be significantly useful for genetic diversity assessment at molecular level. They exhibited high discrimination power, and were able to distinguish the faba bean genotypes with high efficiency and accuracy levels.

Expression patterns of HvCKX genes indicate their role in growth and reproductive development of barley.

Cytokinin oxidase/dehydrogenase proteins (CKX) are encoded by a multigene family of CKX genes with a varying number of members depending on species. For some of the genes, spectacular effects on grain production in selected cereals have been observed. Despite the fact that partial or full length sequences of most HvCKX genes in barley (Hordeum vulgare) have already been published, in most cases their specific biological functions have not been reported. Detailed expression patterns for five HvCKX genes in different organs/tissues of developing barley plants coupled with analysis of RNAi silent for two genes are presented to test the hypothesis that these expression profiles might indicate their function. Elevated expression for four of them – HvCKX1, HvCKX9, HvCKX4, and HvCKX11 – was found in developing kernels of wild-type plants compared to other tissues. HvCKX5 was mainly expressed in leaf tissue. Lower expression was noted for HvCKX1 in seedling roots and for HvCKX9 in leaves. The documented effect of RNAi silencing of HvCKX1 and a trend for HvCKX9 was higher plant productivity, and the trait was inherited through four generations. Higher plant yield was determined by higher numbers of seeds and spikes. Increased productivity was significantly greater in HvCKX1 silenced plants showing higher relative expression of HvCKX1 in developing kernels of wild-type plants compared to the expression of HvCKX9. Both HvCKX1 silenced T1 seedlings of cv. Golden Promise and the newly transformed breeding line STH7308 showed greater root mass, but this trait was not inherited in the next generation. Similarly HvCKX9 silenced T1 seedlings exhibited greater plant height without inheritance in the next generation. It is suggested that these effects were not inherited because of compensation by other genes co-ordinately regulating reproductive development. One line with untypically changed, inherited phenotype, which was selected from several dozen silenced lines showing stable and common phenotypes is presented.

Colonization of an empty island: how does a plant with a plastic gender system respond?

Abstract. Honckenya peploides is the most common plant species on the island of Surtsey. It arrived in 1967 and after a juvenile period of 4 years it produced seeds and had increased its number from below 100 to several millions. Most populations had the individuals distributed in a regular or random pattern, suggesting that intraspecific competition is important. H. peploides has a subdioecious reproductive system consisting of pistillate plants producing capsules, and staminate plants delivering pollen. Some of the latter are in addition producing capsules and are denoted hermaphrodites. Populations at the south coast of Iceland had around equal numbers of pistillate and staminate plants. At Surtsey we found more pistillate plants, probably due to their higher water stress tolerance. We also found a tendency to a higher frequency of hermaphrodite plants with a higher number of seeds per capsule compared to populations at the south coast of Iceland and the nearby island of Heimaey. We suggest that this arises from the time right after the colonization of Surtsey where population size was small and the small generalist pollinators were not able to deposit sufficient pollen on pistillate plants, causing the hermaphrodites to have an advantage by being able to set seed after selfing. The result of this initial advantage of the hermaphrodites in combination with the inheritance of the sexes can still be seen due to the longevity of individuals. A generalized account of the colonization history of H. peploides is given.