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361.
362.
The functional responses of adult and 5th instar Pacific damsel bug,Nabis kinbergii Reuter were determined under laboratory conditions using Australian crop mirid,Sidnia kinbergi (Stal), and pea aphid,Acyrthosiphon pisum (Harris) as prey.Holling's (1959) type II equation was found to adequately define the functional response of this predator except when 5th instar
nymphs were provided with Australian crop mirid as prey. In this instance, a type III response was found.
相似文献
363.
H.J. Clarke J.G. Wilson I. Kuo M.M. Lülsdorf N. Mallikarjuna J. Kuo K.H.M. Siddique 《Plant Cell, Tissue and Organ Culture》2006,85(2):197-204
The main constraint to the transfer of desired traits into cultivated chickpea from wild Cicer relatives is the presence of post-zygotic barriers which result in abortion of the immature embryo following interspecific hybridisation. Rescue of hybrid embryos in vitro and regeneration of hybrid plantlets could allow chickpea breeders to transfer desirable traits from wild relatives of chickpea. The development of embryo rescue techniques using selfed chickpea and selfed wild relatives is being used as a first step to protocols for wide hybrids. Optical microscopy studies of embryogenesis, in both selfs and hybrids, identified deleterious changes in the fertilised hybrid seed as early as 2–4 days after pollination in some crosses. These observations suggest that the appropriate time to rescue chickpea × C. bijugum hybrids is at the early globular stage of embryogenesis (2–7 days old), which requires the development of a complex tissue culture medium. In contrast hybrids between chickpea × C. pinnatifidum abort later (up to 15–20 days old) at the heart-shaped or torpedo stages, and are easier to rescue in vitro. Genotype also plays a significant role in the ability of immature selfed ovules to germinate in vitro. In this paper we report on the optimisation of␣protocols for rescueing immature embryos using selfed chickpea and its wild relatives in ovule, and subsequently to regenerate plantlets. 相似文献
364.
The polymerase chain reaction and nucleotide sequence analysis have been used to characterise two point mutations in the eighth exon of one allele of the C1-inhibitor gene in a kindred with type II hereditary angio-oedema (HAE). The mutations comprise a G to A substitution at C1-inhibitor gene nucleotide 16789 and an upstream C to T substitution at nucleotide position 16765. This represents the first report of these two mutations in the same C1-inhibitor allele in type II HAE. The molecular genetic pathogenesis of HAE is discussed in the light of these findings. 相似文献
365.
Albinism is a common problem encountered in interspecific crosses and tissue culture experiments including anther culture and generation of doubled haploids. It is characterized by partial or complete loss of chlorophyll pigments and incomplete differentiation of chloroplast membranes. This in turn impairs photosynthesis and the plants eventually die at a young stage without reaching maturity. Environmental conditions such as light, temperature, media composition and culture conditions play some role in determining the frequency of albino plant formation. Genetic factors are even more important, and are major determinants in albinism. Genetic studies in different crops show that it is a recessive trait governed by many loci. Both the nuclear and chloroplast genomes affect albinism and incompatibilities between the two are a probable cause of many pigment defects in hybrid progenies. Such incompatibility has been reported in a large number of angiosperms. The mechanisms behind these incompatibilities are poorly understood. Studies of plastid DNA inheritance together with observations using electron microscopy have established that the transmission of plastids can be maternal, paternal or biparental, even within the same genus, especially following wide crosses; contrary to the widespread belief that plastids are almost always transmitted from the maternal parent. Albinism has been overcome in some crop species through somatic hybridization and development of cybrids (cytoplasmic hybrids). However, the strict requirement of efficient protoplast regeneration is a major limitation of these techniques. This review focuses on albinism following interspecific crosses or development of doubled haploids facilitated by tissue culture experiments, underlying mechanisms, and the possibilities for dealing with this important biotechnological limitation. 相似文献
366.