Of course, the term “hybrid rice” is already familiar to farmers, especially in Sumenep Regency. Some farmers have even grown this rice, including Sembada B5, Sembada 16, Sembada 989, Mapan P-05, Arize 6444 Gold, and so on. Although farmers are familiar with hybrid rice and its production potential, some of them are still wondering “what is meant by hybrid rice”, “what is the difference with inbred rice”, and “why hybrid rice seeds are much more expensive than inbred seeds” etc. To our knowledge about hybrid rice, here is some information about hybrid rice.
What is meant by “hybrid rice”?
Hybrid rice is the first offspring (F1) resulting from a cross between male and female parents with superior traits (heterosis). The commercial exploitation of hybrid plants aims to increase production yields by exploiting heterosis. Heterosis, or known as hybrid vigor, generally results in F1 superiority over its parents in, for example, vigor in growth, vitality, reproductive ability, stress resistance, adaptability, production yield, and other traits.
What is the difference between “hybrid rice” and “inbred rice”?
The main difference between hybrid and inbred rice is the type of propagation. Inbred rice like Ciherang, IR 64, Situbagendit, Mekongga, etc. is the result of open pollination, while hybrid rice is the result of crossing female parents (known as CMS line or A-line) and male parents (known as Restorer line or R line). ). Another difference lies in the production process, where hybrid rice has several treatments not found in inbred rice production, such as B. Flower synchronization, use of the hormone GA3 (gibberellin), and artificial pollination.
What are the advantages of hybrid rice?
The superiority of hybrid rice can be seen from 3 aspects, namely morphological character, physiological appearance, and yield. Excellence in morphological characters is shown by:
Better root quantity and quality, including the area of root penetration, root depth, rhizosphere width, number of adventitious roots per plant, and number of root fibers;
ability to produce chicks earlier and faster;
Panicles are larger and heavier.
Manifestation of superiority in physiological appearance, namely in the form of a high seed: straw ratio compared to inbred varieties. This happens because:
Higher root activity from tillering to panicle emergence and even more so during the initial panicle/development phase.
Larger leaf area, therefore the photosynthetic area is also larger
Higher photosynthetic efficiency. This is also associated with an increase in leaf area, so that hybrid rice can produce high-yielding plant populations.
The distribution of assimilation yields was higher in hybrid rice, as indicated by total leaf dry weight.
The third advantage relates to the production results. For years, the facts in the field have shown that hybrid rice yields 20% more than inbred varieties.
Does using hybrid rice have any weaknesses?
The heterosis effect of F1 hybrids cannot be passed to the next generation, so F1 offspring cannot be used as seeds. As a result, farmers have to buy more hybrid rice seeds every time they plant. Another weakness is that hybrid rice is more susceptible to pests, particularly leafhoppers, stem borers, and bacterial leaf blight. Hybrid rice also needs intense environmental conditions to express its heterosis effect, so proper cultivation technology is required, such as through the PTT (Integrated Crop Management) approach for lowland rice.
Why are hybrid rice seeds more expensive than inbred rice seeds?
Hybrid rice seeds are indeed priced more expensive than inbred rice seeds. When the price of inbred rice seed is between IDR 10,000-15,000 per kilo, the price of hybrid rice seed can be over IDR 70,000 per kilo. Why is it so much more expensive? because hybrid rice costs more to produce and has a higher risk of failure, especially when produced domestically. Several factors hampering the development of hybrid rice production in Indonesia are, first, the difficulty of maintaining paddy fields in the form of land, so they are often used for production in isolated periods. Planting times that are out of sync with the environment result in an increased risk of plant pest attack (OPT). Second, is the climatic factor, where the temperature difference between day and night is often extreme. Third, Human Resources (HR) is not sufficient, so they still need intensive support. Furthermore, the price of the parent seeds alone averages over Rp. 1,000,000 per kilo as Indonesia has not yet produced them and therefore has to be imported, so you can already imagine why the production costs are higher. This is one of the reasons why our country still imports the most hybrid rice seeds to meet the needs of the domestic market.
How to produce hybrid rice seeds?
When we talk about hybrid rice seed production methods, it also explains why the price of seeds is higher. 4 basic things differentiate between hybrid and inbred rice seed production, namely use of parents, bloom synchronization, GA3 application, and pollination support.
As mentioned, hybrid rice (F1) is the result of a cross between a female parent (CMS/A line) and a male parent (Restorer/R line), so the presence of the parent is the main requirement in production activities. A line is sterile, meaning it cannot pollinate itself, but it can be pollinated by pollen from other rice plants. While the R-line is a pollinating variety, the A-line pollinates to produce hybrids (F1).
The second requirement is the synchronization of flowering. This stage is also a distinguishing feature in the production of inbred rice seeds. Hybrid rice production depends on the cross-pollination of the two parents, so it is very important to synchronize the timing of panicle release, especially when the growth periods of the two parents are very different. This stage requires a special observation method to predict the timing of panicle release. If there is a significant difference in the observations, it is necessary to immediately take a decision or action to speed up or slow down the duration of growth of one of the elders. The measures taken are in the form of fertilization and/or irrigation management. If flowering synchronization is not achieved, the duration of pollination will be shorter, so many grains will be empty because they will not be fertilized.
The third treatment, which is key to producing high/high semen, is the application of the hormone gibberellin (GA3). This hormone plays a role in stimulating cell elongation. Why is this treatment so important GA3 application makes the A-line panicle complete so the number of seeds opened and filled is more likely to increase the range of stigma, increase plant height and plant later make seedlings appear larger and more productive.
The fourth requirement is assisted pollination, which is accomplished by shaking the R lineage panicles with a rope during flowering to help pollen fly, spread, and pollinate the A lineage. This operation is more effective when there is no wind (breezy). It is generally performed in the morning when the A-line flowers are blooming, and in the afternoon when the R-line flowers are still blooming, even if a few A-line flowers are blooming. Failure to perform this step will have fatal consequences for the production results as many kernels will be empty.
Each growth stage becomes very important and affects the success of hybrid rice production. The question is, are we ready to move forward? Not only to be a hybrid rice seed consumer but also to become a hybrid rice seed producer, thereby minimizing dependence on imported seeds.