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This study aimed to assess the potential for crossbreeding between Susan-e-Chelcharagh ( Lilium ledebourii ), a rare native lilium species in Iran, and selected commercial lily cultivars. Initially, we compared the cytogenetic characteristics of L. ledebourii with several commercial cultivars, followed by crossbreeding attempts using both conventional and cut-style pollination methods. Additionally, we explored the possibility of embryo rescue through ovary slice culture in the maternal parent of the Brindisi cultivar when crossed with L. ledebourii as the paternal parent. Our results revealed that L. ledebourii possesses a diploid ploidy level (2 n  = 2 x = 24) and exhibits high pollen viability (88.5%) and germination rates (77.3%). Crossbreeding endeavors yielded variable fruit formation and growth, with varying success rates in obtaining viable seeds. Notably, the cut-style pollination method proved ineffective in certain commercial cultivars, indicating the presence of pre- and post-fertilization barriers. Findings from the ovary slice culture of the Brindisi maternal parent crossed with L. ledebourii pollen indicated that sucrose and NAA concentrations significantly influenced the survival and enlargement of ovary slices. Optimal ovule germination was observed with 3% sucrose combined with 0.1 mg/L NAA, followed by treatment with 3% sucrose and 0.2 mg/L NAA. Histological analysis further elucidated the presence of post-fertilization barriers in specific crosses, leading to ovule degeneration and failed seed formation. These findings underscore the importance of considering genetic divergence, ploidy levels, and other pertinent factors when undertaking interspecies crosses and hybridization within the Lilium genus.

Hevea brasiliensis Muell. Arg (Para rubber tree) is a tropical tree species of Amazonian origin widely cultivated in several parts of the world for natural rubber, a highly priced commodity inevitable for the world rubber industry. Large, tree to tree variation in growth and latex yield among individual plants of high yielding Hevea clones is a common phenomenon observed in mature rubber plantations. The genetic heterogeneity of the seedlings which are used as rootstocks for propagation through budgrafting is considered as a major factor  responsible for this variation. In order to minimize this variation, attempts were made to develop highly uniform rootstock material via an in vitro technique by inducing zygotic polyembryony in Hevea . Immature open pollinated fruits of a high yielding clone RRII 105 were cultured by half ovulo embryo culture technique. Multiple embryos were induced from the 8–10-week-old zygote with a novel combination of gibberellic acid (GA 3 ), kinetin, and zeatin. Plantlets were successfully generated from the multiple embryos and raised in the field post hardening. Screening using genetic and epigenetic molecular markers revealed that the multiple seedlings developed are highly uniform and are of single zygotic origin. Development of plants having genetic and epigenetic uniformity suggests that this technique is ideal for raising uniform rootstock material in Hevea which may significantly reduce intraclonal variations. Moreover, these plants could serve as ideal material for physiological and molecular investigations towards the understanding of  stock–scion interaction process in rubber.

The plant hormone ethylene regulates a variety of processes of growth and development. To identify components in the ethylene signal transduction pathway, we screened for ethylene-insensitive mutants in Arabidopsis thaliana and isolated a dominant etr2-1 mutant. The etr2-1 mutation confers ethylene insensitivity in several processes, including etiolated seedling elongation, leaf expansion, and leaf senescence. Double mutant analysis indicates that ETR2 acts upstream of CTR1, which codes for a Raf-related protein kinase. We cloned the ETR2 gene on the basis of its map position, and we found that it exhibits sequence homology to the ethylene receptor gene ETR1 and the ETR1-like ERS gene. ETR2 may thus encode a third ethylene receptor in Arabidopsis, transducing the hormonal signal through its \"two-component\" structure. Expression studies show that ETR2 is ubiquitously expressed and has a higher expression in some tissues, including inflorescence and floral meristems, petals, and ovules

In order to enhance the mass production of Musca domestica five aspects of its oviposition biology were analyzed. Oviposition substrate and the manner of its presentation, the composition of the diet of the adults, size of the pupae and numbers of flies in a cage were identified as critical. Females preferred to lay eggs on a substrate which was presented within a shelter and with increased linear edges against which the flies could oviposit. Different types of oviposition substrate resulted in comparable yields of eggs. The presence of an oviposition attractant (ammonia) in the manure was found to have a potentially positive effect on female fecundity. Egg yield increased when two protein sources (yeast and milk) were included in the adult diet. However, flies fed a mixture of sugar and yeast laid over 50% fewer eggs than those fed the same proportion of sugar and milk. The fecundity of flies decreased with the increase in the number of flies per cage, but the highest total number of eggs per cage was obtained with the highest density of flies (14.2 cubic cm per fly). The size of the pupae did not significantly affect egg production.

The nematicidal activity of four molecular weights (2.27 x 10**5, 3.60 x 10**5, 5.97 x 10**5, and 9.47 x 10**5 g/mol) of a biopolymer chitosan was assayed against the root-knot nematode, Meloidogyne incognita, in vitro and in pot experiments. In laboratory assays, the nematode mortality was significantly influenced by exposure times and chitosan molecular weight. Low molecular weight chitosan (2.27 x 10**5 g/mol) was the most effective in killing the nematode with EC50 of 283.47 and 124.90 mg/L after 24 and 48 h of treatment, respectively. In a greenhouse bioassay, all the compounds mixed in soil at one- and five-fold concentrations of the LC50 value significantly reduced population, egg mass, and root galling of tomato seedlings compared with the untreated control. In general, the nematicidal activity of these compounds was increased dramatically with a decrease in the molecular weight. The results suggest that the chitosan at low molecular weight may serve as a natural nematicide.

Muga silkworm is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production.

A phylogenetic analysis of Euphorbiaceae sensu stricto is presented using sequences from rbcL, atpB, matK and 18S rDNA from 85 species and 83 genera. The combined analysis of four molecular markers resulted in only one most parsimonious tree and also generated new supported clades, which include Euphorbioideae + Acalyphoideae s.s., subclades A2 + A3, subclades A5 + A6 and a clade uniting subclades A2-A8 within Acalyphoideae s.s. A palisadal exotegmen is a possible synapomorphy for all the Euphorbiaceae, except for the subfamily Peroideae. The presence of vascular bundles in the inner integument and a thick inner integument were shown to be synapomorphies for the clade of inaperturate and articulated crotonoids and for the large clade of Euphorbioideae, Acalyphoideae s.s., inaperturate and articulated crotonoids, respectively. Characters of the aril and vascular bundles in the outer integument are discussed. The selected embryological characters were seen to be highly correlated with the molecular phylogeny. When the results of molecular phylogenetic analysis of a previous study and this study were adjusted along with the selected embryological characters, all clades within Euphorbiaceae were supported except for a clade comprising Euphorbioideae + Acalyphoideae s.s. + inaperturate crotonoids + articulated crotonoids + Adenoclineae s.l. and a clade uniting subclades A4-A8 within Acalyphoideae s.s.

Prostaglandins are involved in the reproductive processes in a variety of animals, including crustaceans. It was found that polychaetes, the best maturation diet for shrimp broodstock, possessed the greatest variation of prostaglandin Esub(2) (PGEsub(2)) when compared with other live feeds. The level of PGEsub(2) varied according to sizes, feed intake, sources and type of polychaete. The matured and also larger sand polychaete Perinereis sp. contained higher PGEsub(2) levels than younger and smaller sand polychaetes (18.16+-5.82 ng PGEsub(2)/mg protein for polychaetes at an average length of 10 cm up to 160.8+-37.09 ng PGEsub(2)/mg protein for polychaetes at an average length of 17 cm). The PGEsub(2) levels in ovaries and haemolymph of female shrimp fluctuated with the developmental stage of the ovaries. The highest concentration of PGEsub(2) in haemolymph was at stage 3 of ovarian development, whereas the highest concentration of PGEsub(2) in shrimp ovaries was at stage 4. In vitro incubation of Penaeus monodon pre-vitellogenic oocytes with polychaete extract and synthetic PGEsub(2) demonstrated that both PGEsub(2)s enhanced oocyte development, especially during late development and ovulation. The putative role of PGEsub(2) from polychaetes or the presence of PGEsub(2) in polychaetes may be a factor in their role as a dietary constituent required for shrimp oocyte development.

The piggyBac (IFP2) short inverted terminal repeat transposable element from the cabbage looper Trichoplusia ni was tested for gene transfer vector function as part of a bipartite vector-helper system in the Mediterranean fruit fly Ceratitis capitata. A piggyBac vector marked with the medfly white gene was tested with a normally regulated piggyBac transposase helper at two different concentrations in a white eye host strain. Both experiments yielded transformants at an approximate frequency of 3-5%, with a total of six lines isolated having pigmented eyes with various levels of coloration. G1 transformant siblings from each line shared at least one common integration, with several sublines having an additional second integration. For the first transformant line isolated, two integrations were determined to be stable for 15 generations. For five of the lines, a piggyBac-mediated transposition was verified by sequencing the insertion site junctions isolated by inverse PCR that identified a characteristic piggyBac TTAA target site duplication. The efficient and stable transformation of the medfly with a lepidopteran vector represents transposon function over a relatively large evolutionary distance and suggests that the piggyBac system will be functional in a broad range of insects

The mechanisms that initiate reproductive development after fertilization are not understood. Reproduction in higher plants is unique because it is initiated by two fertilization events in the haploid female gametophyte. One sperm nucleus fertilizes the egg to form the embryo. A second sperm nucleus fertilizes the central cell to form the endosperm, a unique tissue that supports the growth of the embryo. Fertilization also activates maternal tissue differentiation, the ovule integuments form the seed coat, and the ovary forms the fruit. To investigate mechanisms that initiate reproductive development, a female-gametophytic mutation termed fie (fertilization-independent endosperm) has been isolated in Arabidopsis. The fie mutation specifically affects the central cell, allowing for replication of the central cell nucleus and endosperm development without fertilization. The fie mutation does not appear to affect the egg cell, suggesting that the processes that control the initiation of embryogenesis and endosperm development are different. FIE/fie seed coat and fruit undergo fertilization-independent differentiation, which shows that the fie female gametophyte is the source of signals that activates sporophytic fruit and seed coat development. The mutant fie allele is not transmitted by the female gametophyte. Inheritance of the mutant fie allele by the female gametophyte results in embryo abortion, even when the pollen bears the wild-type FIE allele. Thus, FIE carries out a novel, essential function for female reproductive development.