Substitution lines are powerful tools for detecting and precisely mapping quantitative trait loci (QTL) in rice. This research involved use of the indica recipient 9311 as the parent and 132 simple sequence repeat markers with polymorphism between parents. We analyzed agronomy traits and substituted segments of 5 advanced backcross substitution lines derived from a backcross of 9311 and a japonica donor, Nipponbare. Compared with 9311, the 5 substitution lines showed statistically significant differences in grain length, grain width, flag leaf length, plant height and seed shattering. The substitution lines had 8 substituted segments, and the total genetic length of the substituted segments was 236.0 cM, mean 29.5 cM. For the recipient 9311 and substitution lines, 7 QTLs (2 for 1 000-grain weight, 1 grain length, 1 grain width, 1 flag leaf length, 1 plant height and 1 seed shattering) on substituted segments distributed on rice chromosomes 1, 3, 5, 6 and 10 were compared by Student t test. The qFll-1 on chromosome 1 controlling flag leaf length and the qPh-6 on chromosome 6 controlling plant height are novel QTL. The results enhanced the quantitative and qualitative knowledge of substitution lines. Identification of the QTL has laid a foundation for fine-mapping QTL and molecular marker-assisted selection for appearance in rice.

We investigated by electron microscopy the ultrastructural character of the mature embryo sac in the chromosome-9 monosomic addition line of Beta corolliflora Zoss. in sugar beet, designated M14. The mature embryo sac of M14 consisted of an egg cell, two synergids, a central cell with a secondary nucleus, and 3-6 antipodal cells. The egg cells in different embryo sacs showed different polarity and metabolic activity. They were classified into three types according to the polarity of egg cells: (1) egg cell with regular polarity—the nucleus was located at the chalazal end, and its cytoplasm was rich in organelles such as ribosomes,
mitochondria and endoplasmic reticulum; (2) egg cell with a nucleus at the micropylar end, and (3) egg cell with a centrally located nucleus. The eggs of the third type contained fewer organelles in cytoplasm. The two synergids degenerated before anthesis in most mature embryo sacs. The secondary nucleus, which was close to the antipodals, showed strong metabolic activity. Both the egg cell and the central cell contained large nuclei with distinct nucleoli and numerous organelles. The egg and the central cell were suggested to be active in metabolism, which could be a label of the autonomous division of unfertilized egg cell and central cell in diplospory.

We report on the microsporogenesis, megasporogenesis and development of female and male gametophytes of Pyrgophyllum yunnanense. Anthers are 2-sporangiate, and the development of anther walls are classified as basic. The tapetum is glandular. The microspore mother cells give rise to isobilateral tetrads by meiosis. Cytokinesis is successive. The mature pollen grains are 2-celled and are shed singly. The ovary is hypostasy and trilocular. The species shows axial placenta with most ovules. The ovule is anatropous, bitegmic and crassinucellate. The chalazal megaspore in a linear or T-shaped tetrad becomes functional. The development of the embryo sac is polygonum. We performed comparative studies with the closely related species Kaempferia rotunda and Caulokaempferia coenobialis. P. yunnanense is closely related to C. coenobialis and is more distant with K. rotunda. P. yunnanense should be treated as an independent genus.

Study of charred cereal seeds collected by sieving and floating from Chengzis han and Xiajiadian sites in Western Liaoning Province indicated that the agriculture was dominated by rain- fed crops in the Middle Bronze Age in the Chengzishan site; as well, the proportion of cultivated foxtail millet was higher than that of broomcorn millet. The Xiajiadian site was a mixed economy of agriculture and pastoralism in the Late Bronze Age. The agriculture in the Xiajiadian site was also dominated by rain-f ed crops of foxtail and broomcorn millet, but the proportion of cultivated broomcorn millet was higher than that in the Chengzishan site (Middle Bronze Age). Drought may be responsible for the increase in broomcornmillet during the Late Bronze Age in the Xiajiadian area. The agriculture systemmay have differed in the Chengzishan and Xiajiadian sites during the Late Bronze Age, but more work is needed to determine the exact time of this differentiation.