Artificial Pollination and Seed Germination of Dendrobium candidum Wall. ex Lindl.

The artificial pollination and the seed germination on Dendrobium candidum were conducted. Results showed that the percentage of fruit-setting reaches the highest under cross pollination before 10 o＇ clock in the morning after blooming 2 d to 4 d. The optimal medium for seeds germination was MS＋ NAA 0.5 mg/L ＋ potato juice 10% ＋ active charcoal 0.5%, and cultured for 7 d in the dark then under light.

A Study on Pollen Viability of Piper colubrinum Link

Pollen viability study on Piper colubrinum Link. carried out to develop interspecific hybridization between P. nigrum L. and P. colubrinum Link.. This plant has good potential as a donor plant in breeding programme for Phytophthora to foot rot resistance in the cultivated species, P. nigrum. This project was carried out to reveal the optimum time to collect pollen of P. colubrinum for artificial pollination. Through this study, anther dehiscence was proved occurred around 9 am. Based on the result obtained from study on the time of anther dehiscence, the pollen was classified into five stages for testing on the viability, i.e., stage 1, before anther dehiscence, i.e., around 7 am （pollen obtained by crushing on the anther）; stage 2： immediately after anther dehiscence, i.e., around 9 am; stage 3： two hours after anther dehiscence, i.e., around 11 am; stage 4： four hours after anther dehiscence, i.e., around 1 pm; and stage 5： six hours after anther dehiscence, i.e., around 3 pm. Data obtained from pollen germination and pollen tube growth study showed that pollen of P. colubrinum was the most viable at two hours after anther dehiscence and onward. It was also proved that the viability can be maintained up to at least eight hours. Pollen obtained before anther dehiscence by crushing on the anther was found less viable with lower percentage of pollen germination and retarded pollen tube growth. In other words, the experiment enlightened that artificial pollination between P. nigrum L. and P. colubrinum Link was ideally to be carded out approximately starting from 11 am until 5 pm, considering the viability of pollen ofP. colubrinum.

Activity of Corn Silk at Different Days after Silk Emergence

This study was carried out to evaluate the changes in silk activity of two corn cultivars Xundan 518 and Yongyou 618 after silk emergence. Artificial pollination was conducted at different days after silk emergence, and the ear length, ear diameter,barren tip length, 100-grain weight, grain number per ear and grain weight per ear were measured at harvest. The results showed that with the delay of pollination, the number and weight of grains per ear increased at first, peaked at D2 to D4, and decreased subsequently; ear diameter and 100-grain weight showed a downward trend. Correlation analysis revealed that grain number per ear and grain weight per ear were most closely correlated. Rapid silk extrusion and long-lasting silk activity proved that the two corn cultivars Xundan 518 and Yongyou 618 are tolerant to high temperature.

The Edible and Medicinal Value of <i>Coix lacryma-jobi</i>and Key Cultivation Techniques for High and Stable Yield

In this paper, it was introduced that Coix lacryma-jobi is a traditional dual-use edible and medicine crops in China, and the nutritional components and medicinal value of Coix lacryma-jobi were described. Based on the published literature at home and abroad, a variety of chemical components found in Coix lacryma jobi and their medicinal effects were reviewed. At the same time, the problems existing in the production of Coix lacryma jobi were put forward. With the improvement of people’s living standards, the nutritional and health care value of Coix lacryma-jobi has been paid more and more attention. The problems of Coix lacryma-jobi in production were analyzed. Some biological characteristics of Coix lacryma-jobi, especially its hygrophyte characteristics, were re-recognized, which is very important to increase the yield of Coix lacryma jobi. In the paper, the key cultivation techniques for high and stable yield of Coix lacryma-jobi were also summarized. In order to obtain high quality, high and stable yield, we should adopt the new technical methods of “two wet, two dry and two water” in water management. At the same time, if artificial pollination is applied in the peak of flowering period, the seed setting rate and the yield will be increased.