[Spatial Relationship between Eco-environment Quality and Land Use Change in Guangdong Province-Hong Kong-Macao, China Based on Remote Sensing-based Ecological Index].

The relationship between eco-environment quality and land use change is an important guarantee for regional sustainable development. Guangdong Province-Hong Kong-Macao have always been closely linked and are now entering a period of accelerated development, but there is a lack of research on the spatial relationship between eco-environment quality and land use change integrated among the three places. Based on historical land use data and Google earth engine （GEE）, MODIS images from the summer of 2000 to 2020 （from June 1 to September 1） were selected （with a time span of five years）.

Induced gynogenesis in grass carp (Ctenopharyngodon idellus) using irradiated sperm of allotetraploid hybrids.

Grass carp (Ctenopharyngodon idellus) eggs were activated by UV-irradiated diploid sperm of allotetraploid hybrids derived from red crucian carp (♀) × common carp (♂) and then duplicated by cold shock in 4-6°C water for 10-12 min. Different cold shock initiation times resulted in two types of diploid gynogenetic grass carp: meiotic gynogenetic (meiG) and mitotic gynogenetic (mitG). Over a 5-year period, a total of 17,170 meiG and 1,080 mitG fry were produced and 6,862 meiG and 372 mitG grass carp survived.

[Remote sensing estimation of vegetation coverage in guangzhou based on the correction of atmospheric radiation].

Vegetation coverage is a basic parameter in describing landscape ecosystem, and an important index in assessing ecosystem health and security. Based on the four TM images in 1990, 1995, 2000 and 2005, and by using the correction model to deduct atmospheric radiation effect and the spatial operating model for TM image under unsupervised classification, the relationship model between vegetation coverage and normalized vegetation index was established, and the vegetation coverage in different phases in Guangzhou was calculated. The results showed that the vegetation coverage in Guangzhou decreased continuously from 1990 to 2000 but began to increase thereafter, which accorded with the economic development and environmental construction of the city.

[The chromosome number and gonadal structure of F9-F11 allotetraploid crucian-carp].

In this paper, the chromosome number of F9-F11 hybridis of Red crucian (Carassius auratus) x common carp(Cryprinus carpio) was examined by means of kidney cell-PHA culture. The results showed that F9-F11 allotetraploids possessed 200 chromosomes, with the karyotype formula 44 m + 68 sm + 44 st + 44 t, which were the same as the data indicated in F3-F8 allotetraploids. Both female and male of F9-F11 allotetraploids had the normal ovaries and testes that were able to produce the normal dipoid ova and sperm.

[Studies of F1 of transgenic allotetraploid hybrids of Carassius auratus red var. (Female) x Cyprinus carpio (Male)].

The tetraploid fish has been developed by assortative breeding the hybrids of Carassius auratus red var. (Female) x cyprinus carpio (Male), which has the stable genetic characters and can reproduce themselves. An "all-fish" recombinant DNA construct (pCAgcGHc) containing common carp beta-actin gene promoter and cDNA for grass carp (Ctenopharyngodon idella) growth hormone gene was introduced into fertilized eggs of the allotetroploid fish through microinjection as soon as artificial insemination was done.