Hydroxycinnamic acid amides in fertile and cytoplasmic male sterile lines of maize

Hydroxycinnamic acid (HCA) amides in fertile and cytoplasmic male sterile lines of maize were determined in reproductive organs, developing grains and cobs. HCA amides occurred in large amounts in the anthers of fertile plants (line F7N) and were absent from the anthers of cytoplasmic male sterile lines (lines F7T and F7C). Restoration of fertility was associated with the production of these compounds (line FC31). Considerable variations were observed in the concentrations of HCA amides at different stages of growth and grain maturation. Changes of HCA amides in the grains which were to produce sterile plants followed a pattern similar to that obtained with the grains which were to produce fertile plants. Accumulation of HCA amides was substantially higher in fertile lines whatever their genotype (F7N, FC31 and F7T x FC31) than in sterile lines. Marked changes occurred in the HCA amide content of embryo and endosperm during grain development. Many changes in HCA amides were observed in cobs during development and maturation, but no substantial differences could be observed between fertile and sterile lines.     

Proteolytic activity in anther extracts of fertile and cytoplasmic male sterile petunia

Proteolytic activity is compared in anther extracts from Petunia parodii fertile and cytoplasmic male sterile lines. It is characterized relative to developmental stage of the anthers, effect of variable incubation times, pH of isolation buffers, and degradation of marker proteins. In fertile anthers, proteolytic activity increases at the end of microsporogenesis and peaks early in microgametogenesis. Degradation is most severe in extracts of fertile anthers and in high molecular weight proteins and reaches its maximum within 20 minutes. Degradation of marker proteins is greatest at pH 5.6 to 8.0 in fertile anther extracts and is eliminated under strong acid conditions (pH 2.8 to 4.0) in both fertile and cytoplasmic male sterile anther extracts. Marker proteins degrade more severely in extracts of fertile anthers; however, the order of substrate sensitivity—myosin > phosphorylase b > bovine serum albumin and ovalbumin > β-galactosidase—is the same in extracts from fertile and cytoplasmic male sterile anthers.     

Changes in protein and amino acid content during anther development in fertile and cytoplasmic male sterile Petunia

Summary Development of anthers in cytoplasmic male sterile (CMS) Petunia diverges from the normal sequence of events early in meiosis. Quantitative and qualitative changes in morphology, proteins and free amino acid contents correlate with this divergence. In anthers of the fertile line (5719), total protein content increases, and SDS-PAGE protein patterns change as the anthers mature. Enhanced levels of three polypeptides with molecular weights of 64,000, 63,000 and 45,000 daltons characterize premeiosis in fertile anthers. Protein levels and patterns from anthers of the CMS line (5707) show little alteration during anther development. Protein synthesis seems to be at least partially blocked in the CMS microspore. The 63,000 and 45,000 dalton proteins are not present, and the absence of any unique protein(s) in the CMS line argues against a virus as the causal agent of CMS in Petunia. Analysis of free amino acids from anthers of the fertile line shows levels of proline and pipecolic acid 2–3 and 10–20 fold higher, respectively, than in the CMS line. The amino acids incorporated into proteins show no such differences; analysis of protein hydrolysates shows similar levels of each amino acid in both fertile and CMS lines at every developmental stage examined.     

Developmental and morphological analyses of homeotic cytoplasmic male sterile and fertile carrot flowers

Floral development and morphology were observed for two homeotic cytoplasmic male sterile carrot lines and their isonuclear fertile maintainers. For one sterile line, W33A stamens are replaced by petal-like organs; for the other, W259A, both stamens and petals are replaced by green bract-like structures. Both isonuclear maintainers, W33B and W259B respectively, have stamens and white petals. The different sterile phenotypes result from the interactions of distinct nuclear genotypes with one sterility-inducing cytoplasm. Early stages of floral development were similar among all four lines; the third whorl primordia were radial while those in the second whorl were dorsiventral. However, the third whorl primordia were splayed outward in the sterile lines and inward in the fertile lines. Subsequently, radial anthers on filaments differentiated in fertile lines and dorsiventral hastate and cordate shaped structures appeared in W33A and W259A, respectively. In the mature flower, the third whorl organs were cordate in W33A and ovate in W259A. Based on epidermal cell morphology, the second whorl organs of the two sterile lines had characteristics of both petals and bracts, but of opposite degrees; cells of W33A and W259A were most similar to those of petals and bracts, respectively. The third whorl organs of the sterile lines had characteristics of their respective second whorl organs; however, structures of W33A also had filament-like cells and those of W259A were more bract-like than their respective second whorl organs. The cytoplasm affected when homeosis was manifested during development. Nuclear factors interacting with cytoplasm were most important for determining differentiation. The significance of cytoplasm to current models of nuclear-gene-controlled homeosis is discussed.     

Differences on the microsporogenesis and tapetal development of male fertile and cytoplasmic male sterile pepper (Capsicum annuum L.)

To clarify the time and cause of pollen abortion, differences on the microsporogenesis and tapetum development in the anthers of male fertile maintainer line and cytoplasmic male sterile (CMS) line pepper were studied using transmission electron microscopy. The results showed that CMS line anthers appeared to have much greater variability in developmental pattern than male fertile maintainer line ones. The earliest deviation from normal anther development occurred in CMS line anthers at prophase I was cytomixis in some microspore mother cells (MMCs), and vacuolisation in tapetal cells. Then, MMCs in CMS line anthers developed asynchronously and a small part of ones at the different stage degenerated in advance appearing to have typical morphological features of programmed cell death (PCD). Most MMCs could complete the meiosis, but formed non-tetrahedral tetrad microspores with irregular shape and different size and uncertain number of nuclei, and some degenerated ahead of time as well. Tapetal cells in CMS line anther degenerated during meiosis, and were crushed at the tetrad stage, which paralleled the collapse of pollens. Pollen abortion in CMS line anthers happened by PCD themselves, and the premature PCD of tapetal cells were closely associated with male sterility.     

Histological aspects of microsporogenesis in fertile,cytoplasmic male sterile and restored fertilePetunia hybrida

Summary A comparative histological study is made of microsporogenesis in fertile, cytoplasmic male sterile and restored fertilePetunia. Microsporogenesis in sterile anthers proceeds normally until leptotene. The development of the restored fertile type at 25°C is normal until the tetrad stage. In both types sporogenesis arrests and the meiocytes, c.q. microspores ultimately degenerate. The first phenomena of deviation are found in the tapetum. The effects of degeneration on cellular structure, vacuolation and cytoplasmic organization of the tapetal and sporogenous cells are variable. The deposition of callose around the meiocytes appears independent of the process of degeneration. The absence of an increase in callase activity possibly explains the remnants of callose found at late stages of development. The failure of callose wall dissolution appears to be the result of metabolic abnormalities in the tapetum and is regarded as an indirect effect of sterility.     

QTL analysis of fertility restoration in cytoplasmic male sterile pepper

Fertility restoration of Petersons cytoplasmic male-sterility in pepper (Capsicum annuum L.) is quantitative and environment-dependent. QTL analysis of fertility restoration was performed based on the test-cross progeny of 77013A (a strict cytoplasmic-genetic male sterile line) and a doubled haploid population of 114 lines obtained from an F₁ hybrid between Yolo wonder (a sterility maintainer line) and Perennial (a fertility-restorer line). The fertility of the test-crossed lines was assessed under greenhouse and open field conditions using three criteria related to pollen or seed production. One major QTL for fertility restoration was mapped to chromosome P6. It was significant in all the environments and for all the traits, accounting for 20–69% of the phenotypic variation, depending on the trait. Four additional minor QTLs were also detected on chromosomes P5, P2, and linkage groups PY3 and PY1, accounting for 7–17% of the phenotypic variation. Most of the alleles increasing fertility originated from the restorer parent, except for two alleles at minor QTLs. Phenotypic analysis and genetic dissection indicated that breeding pepper for complete sterility of female lines and high hybrid fertility requires complex combinations of alleles from both parents and a strict control of the environment.     

Organizational differences between cytoplasmic male sterile and male fertile Brassica mitochondrial genomes are confined to a single transposed locus.

Comparison of the physical maps of male fertile (cam) and male sterile (pol) mitochondrial genomes of Brassica napus indicates that structural differences between the two mtDNAs are confined to a region immediately upstream of the atp6 gene. Relative to cam mtDNA, pol mtDNA possesses a 4.5 kb segment at this locus that includes a chimeric gene that is cotranscribed with atp6 and lacks an approximately 1kb region located upstream of the cam atp6 gene. The 4.5 kb pol segment is present and similarly organized in the mitochondrial genome of the common nap B.napus cytoplasm; however, the nap and pol DNA regions flanking this segment are different and the nap sequences are not expressed. The 4.5 kb CMS-associated pol segment has thus apparently undergone transposition during the evolution of the nap and pol cytoplasms and has been lost in the cam genome subsequent to the pol-cam divergence. This 4.5 kb segment comprises the single DNA region that is expressed differently in fertile, pol CMS and fertility restored pol cytoplasm plants. The finding that this locus is part of the single mtDNA region organized differently in the fertile and male sterile mitochondrial genomes provides strong support for the view that it specifies the pol CMS trait.     

Somatic hybridization in Petunia: A male sterile cytoplasmic hybrid

Fusion was induced between leaf mesophyll protoplasts of a cytoplasmic male sterile (cms) and a fertile petunia line. The selection system was designed to allow only the growth of protoplasts possessing the genome of the fertile line. The majority of plants which were regenerated from protoplasts were phenotypically similar to the fertile line. Some of these plants were cytoplasmic hybrids (cybrids), combining the (S) cytoplasm from the male sterile line with the genome of the fertile line.     

Surface configuration of mesothelial cells in effusions. A comparative light microscopic and scanning electron microscopic study.

Surface configuration of mesothelial cells identified by light microscopy (LM) has been studied by scanning electron microscopy (SEM). It has been shown that mesothelial cells may have a variable SEM appearance. The surfaces of a small proportion of mesothelial cells are covered by regular microvilli (MV) and show openings of the pinocytotic vesicles. The surfaces of the majority of these cells are covered by vesicles or blebs. An intermediate population of mesothelial cells, i.e., cells displaying side-by-side blebs and MV, has also been observed. The latter cells no longer display pinocytotic vesicles. Occasional mesothelial cells have smooth surfaces. It has been shown by LM and transmission electron microscopy that cells with blebs are viable and capable of mitotic activity. It is concluded that mesothelial cells, detached from their epithelial setting, lose microvilli and pinocytotic vesicles and acquire surface blebs. The possible relationship between mesothelial cells and macrophages based on surface features has been discussed.     

Molecular analysis of a new cytoplasmic male sterile genotype in sunflower.

Mitochondrial DNA from 1 fertile and 6 cytoplasmic male sterile (CMS) sunflower genotypes was studied. The CMS genotypes had been obtained either by specific crosses between different Helianthus species or by mutagenesis. CMS-associated restriction fragment length polymorphisms (RFLPs) were found in the vicinity of the atpA locus, generated by various restriction enzymes. The organization of the mitochondrial genes 26S rRNA, 18S + 5S rRNA and coxII was investigated by Southern blot analysis. These genes have similar structures in fertile and all studied sterile sources. Using the atpA probe, 5 from the 6 investigated CMS genotypes showed identical hybridization patterns to the Petiolaris CMS line, which is used in all commercial sunflower hybrids. Only 1 cytoplasm derived from an open pollination of Helianthus annuus ssp. texanus, known as ANT1, contained a unique mitochondrial DNA fragment, which is distinguishable from the fertile and sterile Petiolaris genotypes and from all investigated CMS genotypes. Male fertility restoration and male sterility maintenance of the ANT1 line are different from the Petiolaris CMS system, which is a confirmation that a novel CMS genotype in sunflower has been identified.     

A light and electron microscopic study of mitosis inBullera alba and the histochemistry of some cytoplasmic substances

Summary Mitosis in the imperfect yeast-like basidiomyceteBullera alba was studied by comparative light and electron microscopy. During mitosis the chromatin containing part of the nucleus moved into the progeny cell, and the nucleolus containing part of the nucleus remained in the parent cell. The two portions of the nucleus then separated and the nucleolar part degenerated. Metaphase and anaphase took place in the progeny cell. Subsequently one mass of chromatin returned to the parent cell, and two new nuclei were formed. The study concentrated on the nuclear envelope, nucleolus, spindle pole body, chromatin, spindle, and cytoplasmic microtubules. Mitosis inB. alba was compared with reports of mitosis in other basidiomycetes, theUredinales, and theAscomycotina and was deemed closest to the heterobasidiomycete yeasts.Histochemical evidence for the presence of lipid, glycogen, and polyphosphate in the cytoplasm was presented.     

空间环境诱发玉米细胞质雄性不育突变体的遗传分析

从返回式卫星"实践八号"搭载的08-641和18-599两份玉米自交系后代选育出3份雄性不育突变体,在不同地点、不同年份、不同季节进行种植观察,鉴定其育性表现,通过测交、反交及回交对不育性状的遗传特性进行分析。结果表明:3份不育突变材料均能稳定遗传,属可遗传的细胞质雄性不育类型。恢保关系测定和特异引物PCR扩增结果显示,3份不育材料均属玉米C型细胞质雄性不育类型,但3份不育材料在恢保关系上存在一定差异,推测它们可能分别属于玉米C型细胞质雄性不育的不同亚组。这些不育材料的发现,丰富了雄性不育胞质的遗传基础,在玉米不育化制种中具有一定应用价值。     

Pollen development in male sterile mangosteen (Garcinia mangostana L.) and male fertile seashore mangosteen (Garcinia celebica L.)

Protoplasma - Mangosteen (Garcinia mangostana L.) is an economically important tropical fruit, yet the reproductive biology of this dioecious plant is complex. Male trees are not known, and female...     

A comparative study of the atp9 gene between a cytoplasmic male sterile line and its maintainer line and further development of a molecular marker specific for male sterile cytoplasm in kenaf (Hibiscus cannabinus L.)

mtDNA was isolated from cytoplasmic male sterility (CMS) line P3A and its maintainer P3B of kenaf (Hibiscus cannabinus L.). The atp9 gene and its two flanking sequences were obtained using homology cloning and high-efficiency thermal asymmetric interlaced PCR methods. The coding sequences showed only two base pairs difference between the CMS and its maintainer, and shared a homology of over 87 % with atp9 genes from other species in GenBank. However, when comparing the flanking sequences, a 47-bp deletion was characterized at the 3′ flanking sequence of atp9 in the CMS line. Quantitative PCR analysis indicated that the expression level of atp9 in the CMS line was 0.937-fold that of its maintainer. Furthermore, the respiratory rate of anthers in the CMS line was markedly lower than that of its maintainer. The results indicated that the 47-bp deletion at the 3′ flanking sequence of atp9 and/or down-regulated expression of the atp9 gene in the CMS line might be closely related to CMS in kenaf. To confirm whether the 47-bp deletion was specific to cytoplasm of male sterile lines, another 21 varieties were used for further analysis. The results showed that the 47-bp deletion was specific to male sterile cytoplasm (MSC) of kenaf. Based on these, a specific molecular marker was developed to distinguish the MSC from male fertile cytoplasm of kenaf.